diff --git a/games/static/js/search_select.js b/games/static/js/search_select.js
index 0a96652..6303751 100644
--- a/games/static/js/search_select.js
+++ b/games/static/js/search_select.js
@@ -21,158 +21,190 @@
  * and data-* attributes — so all markup and Tailwind class strings live in one
  * place (the Python components), never duplicated here.
  */
-(function () {
+(() => {
   "use strict";
 
-  var DEBOUNCE_MS = 100;
+  const DEBOUNCE_MS = 100;
 
   // Must match Python common/components/filters.py:_PRESENCE_MODIFIERS.
   // These modifiers are mutually exclusive with value pills — selecting
   // one clears all value pills.  Non-presence modifiers (INCLUDES_ALL,
   // INCLUDES_ONLY) coexist with value pills.
-  var PRESENCE_MODIFIERS = ["NOT_NULL", "IS_NULL"];
+  const PRESENCE_MODIFIERS = ["NOT_NULL", "IS_NULL"];
 
-  function initAll() {
-    document.querySelectorAll("[data-search-select]").forEach(function (element) {
+  const initAll = () => {
+    document.querySelectorAll("[data-search-select]").forEach(element => {
       if (element._searchSelectInit) return;
       element._searchSelectInit = true;
       initWidget(element);
     });
-  }
+  };
 
-  function initWidget(container) {
-    var search = container.querySelector("[data-search-select-search]");
-    var options = container.querySelector("[data-search-select-options]");
-    var pills = container.querySelector("[data-search-select-pills]");
+  const initWidget = (container) => {
+    const search = container.querySelector("[data-search-select-search]");
+    const options = container.querySelector("[data-search-select-options]");
+    const pills = container.querySelector("[data-search-select-pills]");
     if (!search || !options || !pills) return;
 
-    var name = container.getAttribute("data-name");
-    var searchUrl = container.getAttribute("data-search-url");
-    var isFilter = container.getAttribute("data-search-select-mode") === "filter";
-    var multi = container.getAttribute("data-multi") === "true";
-    var alwaysVisible = container.getAttribute("data-always-visible") === "true";
-    var itemsScroll = parseInt(container.getAttribute("data-items-scroll"), 10) || 10;
-    var prefetch = parseInt(container.getAttribute("data-prefetch"), 10) || 0;
-    var syncUrl = container.getAttribute("data-sync-url") === "true";
+    const name = container.getAttribute("data-name");
+    const searchUrl = container.getAttribute("data-search-url");
+    const isFilter = container.getAttribute("data-search-select-mode") === "filter";
+    const multi = container.getAttribute("data-multi") === "true";
+    const alwaysVisible = container.getAttribute("data-always-visible") === "true";
+    const prefetch = parseInt(container.getAttribute("data-prefetch"), 10) || 0;
+    const syncUrl = container.getAttribute("data-sync-url") === "true";
 
-    var noResults = options.querySelector("[data-search-select-no-results]");
-    var debounceTimer = null;
-    var pendingRequest = null; // in-flight AbortController, so newer queries win
-    var hasPrefetched = false;
+    const noResults = options.querySelector("[data-search-select-no-results]");
+    let debounceTimer = null;
+    let pendingRequest = null; // in-flight AbortController, so newer queries win
+    let hasPrefetched = false;
 
-    function hasVisibleContent() {
-      var optionRows = options.querySelectorAll("[data-search-select-option]");
-      for (var i = 0; i < optionRows.length; i++) {
+    const hasVisibleContent = () => {
+      const optionRows = options.querySelectorAll("[data-search-select-option]");
+      for (let i = 0; i < optionRows.length; i++) {
         if (optionRows[i].style.display !== "none") return true;
       }
       if (noResults && !noResults.classList.contains("hidden")) return true;
       if (options.querySelector("[data-search-select-modifier-option]")) return true;
       return false;
-    }
+    };
 
-    function showPanel() {
+    const showPanel = () => {
       if (alwaysVisible || hasVisibleContent()) {
         options.classList.remove("hidden");
       }
-    }
-    function hidePanel() {
+    };
+    const hidePanel = () => {
       if (!alwaysVisible) options.classList.add("hidden");
-    }
+    };
 
-    function setNoResults(visible) {
+    const setNoResults = (visible) => {
       if (!noResults) return;
       noResults.classList.toggle("hidden", !visible);
       if (visible) showPanel();
-    }
+    };
 
     // ── Highlight tracking (filter mode) ──
-    var highlightedRow = null;
+    let highlightedRow = null;
 
-    function highlightOption(row) {
+    const highlightOption = (row) => {
       clearHighlight();
       if (!row) return;
       row.setAttribute("data-search-select-highlighted", "");
       highlightedRow = row;
       row.scrollIntoView({ block: "nearest" });
-    }
+    };
 
-    function clearHighlight() {
+    const clearHighlight = () => {
       if (highlightedRow) {
         highlightedRow.removeAttribute("data-search-select-highlighted");
         highlightedRow = null;
       }
-    }
+    };
 
-    function getVisibleOptions() {
-      var all = options.querySelectorAll("[data-search-select-option]");
-      return Array.prototype.filter.call(all, function (row) {
-        return row.style.display !== "none";
-      });
-    }
+    const getVisibleOptions = () => {
+      const all = options.querySelectorAll("[data-search-select-option]");
+      return Array.from(all).filter(row => row.style.display !== "none");
+    };
 
-    function autoHighlight(query) {
-      var visible = getVisibleOptions();
+    const autoHighlight = (query) => {
+      const visible = getVisibleOptions();
       if (visible.length === 0) {
         clearHighlight();
         return;
       }
-      var lower = query.toLowerCase();
+      const lower = query.toLowerCase();
       // 1. Starts-with match
-      for (var i = 0; i < visible.length; i++) {
-        var label = (visible[i].getAttribute("data-label") || "").toLowerCase();
+      for (let i = 0; i < visible.length; i++) {
+        const label = (visible[i].getAttribute("data-label") || "").toLowerCase();
         if (lower && label.startsWith(lower)) {
           highlightOption(visible[i]);
           return;
         }
       }
       // 2. Substring match (fuzzy-lite)
-      for (var j = 0; j < visible.length; j++) {
-        var subLabel = (visible[j].getAttribute("data-label") || "").toLowerCase();
-        if (lower && subLabel.indexOf(lower) !== -1) {
+      for (let j = 0; j < visible.length; j++) {
+        const subLabel = (visible[j].getAttribute("data-label") || "").toLowerCase();
+        if (lower && subLabel.includes(lower)) {
           highlightOption(visible[j]);
           return;
         }
       }
       // 3. Fallback: first visible option
       highlightOption(visible[0]);
-    }
+    };
+
+    // Get active values in both form and filter modes
+    const getSelectedValues = () => {
+      const vals = new Set();
+      pills.querySelectorAll('input[type="hidden"]').forEach(input => {
+        vals.add(input.value);
+      });
+      pills.querySelectorAll("[data-pill]").forEach(pill => {
+        const val = pill.getAttribute("data-value");
+        if (val) vals.add(val);
+      });
+      return vals;
+    };
 
     // ── Render server-fetched rows into the panel ──
-    function renderRows(items) {
-      options.querySelectorAll("[data-search-select-option]").forEach(function (row) {
+    const renderRows = (items) => {
+      const selectedVals = getSelectedValues();
+      const preservedOptions = [];
+
+      // Extract existing option data for currently selected values before removing
+      options.querySelectorAll("[data-search-select-option]").forEach(row => {
+        const val = row.getAttribute("data-value");
+        if (selectedVals.has(val)) {
+          preservedOptions.push(optionFromRow(row));
+        }
         row.remove();
       });
-      items.slice(0, itemsScroll).forEach(function (item) {
-        options.insertBefore(buildRow(item), noResults || null);
+
+      const renderedValues = new Set();
+
+      // Render preserved options first (to keep them at the top)
+      preservedOptions.forEach(opt => {
+        options.insertBefore(buildRow(opt), noResults || null);
+        renderedValues.add(String(opt.value));
       });
+
+      // Render newly fetched items (excluding already rendered preserved ones)
+      // Fix DOM-limit vs fetch mismatch: Do not slice the items, render all returned items.
+      items.forEach(item => {
+        if (!renderedValues.has(String(item.value))) {
+          options.insertBefore(buildRow(item), noResults || null);
+          renderedValues.add(String(item.value));
+        }
+      });
+
       showPanel();
-    }
+    };
 
     // ── Clone a server-rendered <template> prototype by name. The server emits
     //    the mode-appropriate prototypes, so the JS never names a class. ──
-    function cloneTemplate(name) {
-      var template = container.querySelector('template[data-search-select-template="' + name + '"]');
+    const cloneTemplate = (name) => {
+      const template = container.querySelector(`template[data-search-select-template="${name}"]`);
       return template
         ? template.content.firstElementChild.cloneNode(true)
         : null;
-    }
+    };
 
-    function setLabel(node, label) {
-      var slot = node.querySelector("[data-search-select-label]");
+    const setLabel = (node, label) => {
+      const slot = node.querySelector("[data-search-select-label]");
       if (slot) slot.textContent = label;
-    }
+    };
 
-    function applyData(node, data) {
-      data = data || {};
-      Object.keys(data).forEach(function (key) {
-        node.setAttribute("data-" + key, data[key]);
+    const applyData = (node, data = {}) => {
+      Object.keys(data).forEach(key => {
+        node.setAttribute(`data-${key}`, data[key]);
       });
-    }
+    };
 
     // Build an option row by cloning the "row" template (the same prototype the
     // server renders, so fetched and pre-rendered rows are identical).
-    function buildRow(option) {
-      var row = cloneTemplate("row");
+    const buildRow = (option) => {
+      const row = cloneTemplate("row");
       if (!row) return document.createComment("ss-row");
       row.setAttribute("data-value", option.value);
       row.setAttribute("data-label", option.label);
@@ -180,59 +212,57 @@
       setLabel(row, option.label);
       row._searchSelectOption = option;
       return row;
-    }
+    };
 
     // ── Client-side filter of the currently loaded rows. Returns the number of
     //    visible rows so the caller decides whether to show the no-results node. ──
-    function filterRows(query) {
-      var lower = query.toLowerCase();
-      var visibleCount = 0;
-      options.querySelectorAll("[data-search-select-option]").forEach(function (item) {
-        var label = (item.getAttribute("data-label") || "").toLowerCase();
-        var match = label.indexOf(lower) !== -1;
+    const filterRows = (query) => {
+      const lower = query.toLowerCase();
+      let visibleCount = 0;
+      options.querySelectorAll("[data-search-select-option]").forEach(item => {
+        const label = (item.getAttribute("data-label") || "").toLowerCase();
+        const match = label.includes(lower);
         item.style.display = match ? "" : "none";
         if (match) visibleCount += 1;
       });
       return visibleCount;
-    }
+    };
 
     // ── Fetch matching rows from the server. The previous in-flight request is
     //    aborted so a slower earlier response can never overwrite a newer one. ──
-    function fetchFromServer(query) {
+    const fetchFromServer = (query) => {
       if (pendingRequest) pendingRequest.abort();
       pendingRequest = new AbortController();
-      var url = searchUrl + "?q=" + encodeURIComponent(query);
-      if (prefetch && !query) url += "&limit=" + prefetch;
+      let url = `${searchUrl}?q=${encodeURIComponent(query)}`;
+      if (prefetch && !query) url += `&limit=${prefetch}`;
       fetch(url, { credentials: "same-origin", signal: pendingRequest.signal })
-        .then(function (response) {
-          return response.json();
-        })
-        .then(function (items) {
+        .then(response => response.json())
+        .then(items => {
           pendingRequest = null;
           renderRows(items);
           // Re-apply the live query: the box may hold more text than was sent.
           setNoResults(filterRows(search.value.trim()) === 0);
           autoHighlight(search.value.trim());
         })
-        .catch(function (error) {
-          if (error && error.name === "AbortError") return; // superseded
+        .catch(error => {
+          if (error?.name === "AbortError") return; // superseded
           pendingRequest = null;
           setNoResults(true);
         });
-    }
+    };
 
     // Called on every keystroke. With a search_url, filter the loaded window
     // instantly (zero latency) and debounce a server request for the rest;
     // no-results stays hidden until the response decides it, to avoid a flash
     // over an incomplete window. Without a search_url the loaded set is complete,
     // so the client-side filter is authoritative.
-    function runSearch() {
-      var query = search.value.trim();
+    const runSearch = () => {
+      const query = search.value.trim();
       if (searchUrl) {
         filterRows(query);
         setNoResults(false);
         clearTimeout(debounceTimer);
-        debounceTimer = setTimeout(function () {
+        debounceTimer = setTimeout(() => {
           fetchFromServer(query);
         }, DEBOUNCE_MS);
       } else {
@@ -240,13 +270,13 @@
       }
       autoHighlight(query);
       showPanel();
-    }
+    };
 
     // ── Single-select combobox: the search box shows the committed label;
     //    focusing clears it to search, blurring restores it (or deselects). ──
     if (!multi) container._searchSelectLabel = search.value;
 
-    search.addEventListener("focus", function () {
+    search.addEventListener("focus", () => {
       if (!multi) {
         // Hide the committed label so the box becomes a fresh search field.
         search.value = "";
@@ -269,15 +299,17 @@
       }
       showPanel();
     });
-    search.addEventListener("input", function () {
+
+    search.addEventListener("input", () => {
       clearHighlight();
       if (!multi) container._searchSelectDirty = true;
       runSearch();
     });
+
     if (!multi) {
-      search.addEventListener("blur", function () {
+      search.addEventListener("blur", () => {
         // Defer so an option click (which fires before blur settles) wins.
-        setTimeout(function () {
+        setTimeout(() => {
           if (container._searchSelectDirty && search.value.trim() === "") {
             // User intentionally cleared the box → deselect.
             pills.innerHTML = "";
@@ -293,10 +325,10 @@
     }
 
     // ── Keyboard navigation (both form and filter modes) ──
-    search.addEventListener("keydown", function (event) {
-      var key = event.key;
-      if (key !== "ArrowDown" && key !== "ArrowUp" && key !== "Enter" && key !== "Escape") return;
-      var visible = getVisibleOptions();
+    search.addEventListener("keydown", (event) => {
+      const { key } = event;
+      if (!["ArrowDown", "ArrowUp", "Enter", "Escape"].includes(key)) return;
+      const visible = getVisibleOptions();
       if (visible.length === 0) {
         if (key === "Escape") hidePanel();
         return;
@@ -305,17 +337,17 @@
       if (key === "ArrowDown") {
         event.preventDefault();
         showPanel();
-        var downIdx = highlightedRow ? visible.indexOf(highlightedRow) : -1;
+        const downIdx = highlightedRow ? visible.indexOf(highlightedRow) : -1;
         highlightOption(visible[(downIdx + 1) % visible.length]);
       } else if (key === "ArrowUp") {
         event.preventDefault();
         showPanel();
-        var upIdx = highlightedRow ? visible.indexOf(highlightedRow) : -1;
+        const upIdx = highlightedRow ? visible.indexOf(highlightedRow) : -1;
         highlightOption(visible[(upIdx - 1 + visible.length) % visible.length]);
       } else if (key === "Enter") {
         if (highlightedRow) {
           event.preventDefault();
-          var option = optionFromRow(highlightedRow);
+          const option = optionFromRow(highlightedRow);
           if (isFilter) {
             addFilterPill(option, "include");
             search.value = "";
@@ -332,24 +364,24 @@
     });
 
     // Clicking an option must not blur the input before the click selects.
-    options.addEventListener("mousedown", function (event) {
+    options.addEventListener("mousedown", (event) => {
       event.preventDefault();
     });
 
     // ── Option click → select (form mode) or include/exclude (filter mode) ──
-    options.addEventListener("click", function (event) {
+    options.addEventListener("click", (event) => {
       if (isFilter) {
         handleFilterOptionClick(event);
         return;
       }
-      var row = event.target.closest("[data-search-select-option]");
+      const row = event.target.closest("[data-search-select-option]");
       if (!row) return;
       selectOption(optionFromRow(row));
     });
 
-    function handleFilterOptionClick(event) {
+    const handleFilterOptionClick = (event) => {
       // Pinned modifier pseudo-option → set the (mutually exclusive) modifier.
-      var modifierRow = event.target.closest("[data-search-select-modifier-option]");
+      const modifierRow = event.target.closest("[data-search-select-modifier-option]");
       if (modifierRow) {
         setModifier(
           modifierRow.getAttribute("data-search-select-modifier-option"),
@@ -358,85 +390,84 @@
         return;
       }
       // Include / exclude button on a value row.
-      var button = event.target.closest("[data-search-select-action]");
+      const button = event.target.closest("[data-search-select-action]");
       if (button) {
-        var row = button.closest("[data-search-select-option]");
+        const row = button.closest("[data-search-select-option]");
         if (!row) return;
         addFilterPill(optionFromRow(row), button.getAttribute("data-search-select-action"));
         return;
       }
       // Click on the option row itself → include.
-      var optionRow = event.target.closest("[data-search-select-option]");
+      const optionRow = event.target.closest("[data-search-select-option]");
       if (optionRow) {
         addFilterPill(optionFromRow(optionRow), "include");
-        return;
       }
-    }
+    };
 
     // Add (or re-type) an include/exclude pill for a value. Selecting any value
     // clears a presence modifier — NOT_NULL / IS_NULL are mutually exclusive
     // with value pills.  Non-presence modifiers (INCLUDES_ALL / INCLUDES_ONLY)
     // persist alongside value pills.
-    function addFilterPill(option, kind) {
-      var modPill = pills.querySelector("[data-search-select-modifier]");
+    const addFilterPill = (option, kind) => {
+      const modPill = pills.querySelector("[data-search-select-modifier]");
       if (modPill) {
-        var modVal = modPill.getAttribute("data-search-select-modifier");
-        if (PRESENCE_MODIFIERS.indexOf(modVal) !== -1) {
+        const modVal = modPill.getAttribute("data-search-select-modifier");
+        if (PRESENCE_MODIFIERS.includes(modVal)) {
           clearModifier();
         }
       }
-      var existing = pills.querySelector(
-        '[data-pill][data-value="' + cssEscape(option.value) + '"]'
+      const existing = pills.querySelector(
+        `[data-pill][data-value="${cssEscape(option.value)}"]`
       );
       if (existing) existing.remove();
       pills.appendChild(buildFilterValuePill(option, kind));
       search.value = "";
       emitChange(null);
-    }
+    };
 
-    function buildFilterValuePill(option, kind) {
-      var pill = cloneTemplate(kind === "include" ? "pill-include" : "pill-exclude");
+    const buildFilterValuePill = (option, kind) => {
+      const pill = cloneTemplate(kind === "include" ? "pill-include" : "pill-exclude");
       pill.setAttribute("data-value", option.value);
       pill.setAttribute("data-label", option.label);
       applyData(pill, option.data);
       setLabel(pill, option.label);
       return pill;
-    }
+    };
 
     // Set the modifier pill.  Presence modifiers (NOT_NULL / IS_NULL) clear all
     // value pills — they are mutually exclusive.  Non-presence modifiers
     // (INCLUDES_ALL / INCLUDES_ONLY) are prepended before existing value pills.
-    function setModifier(modifierValue, label) {
+    const setModifier = (modifierValue, label) => {
       // Remove any existing modifier pill to avoid duplicates.
       clearModifierPill();
-      if (PRESENCE_MODIFIERS.indexOf(modifierValue) !== -1) {
+      if (PRESENCE_MODIFIERS.includes(modifierValue)) {
         pills.innerHTML = "";
       }
-      var pill = cloneTemplate("pill-modifier");
+      const pill = cloneTemplate("pill-modifier");
       pill.setAttribute("data-search-select-modifier", modifierValue);
       setLabel(pill, label);
       pills.insertBefore(pill, pills.firstChild);
       container.setAttribute("data-modifier", modifierValue);
       hidePanel();
       emitChange(null);
-    }
+    };
 
     // Remove the modifier pill and its container attribute.  Safe to call when
     // there is no modifier pill (no-op).  Does not touch value pills.
-    function clearModifierPill() {
-      var modifierPill = pills.querySelector("[data-search-select-modifier]");
+    const clearModifierPill = () => {
+      const modifierPill = pills.querySelector("[data-search-select-modifier]");
       if (modifierPill) modifierPill.remove();
       container.removeAttribute("data-modifier");
-    }
+    };
 
-    function clearModifier() {
+    const clearModifier = () => {
       clearModifierPill();
-    }
+    };
 
-    function optionFromRow(row) {
+    const optionFromRow = (row) => {
       if (row._searchSelectOption) return row._searchSelectOption;
-      var data = {};
-      Object.keys(row.dataset).forEach(function (key) {
+      const data = {};
+      Object.keys(row.dataset).forEach(key => {
         if (key !== "value" && key !== "label" && key !== "ssOption") {
           data[key] = row.dataset[key];
         }
@@ -444,13 +475,13 @@
       return {
         value: row.getAttribute("data-value"),
         label: row.getAttribute("data-label"),
-        data: data,
+        data,
       };
-    }
+    };
 
-    function selectOption(option) {
+    const selectOption = (option) => {
       if (multi) {
-        if (!pills.querySelector('input[value="' + cssEscape(option.value) + '"]')) {
+        if (!pills.querySelector(`input[value="${cssEscape(option.value)}"]`)) {
           addPill(option);
         }
       } else {
@@ -464,36 +495,36 @@
         hidePanel();
       }
       emitChange(option);
-    }
+    };
 
-    function addPill(option) {
-      var pill = buildPill(option);
+    const addPill = (option) => {
+      const pill = buildPill(option);
       if (pill) pills.appendChild(pill);
       pills.appendChild(buildHidden(option.value));
-    }
+    };
 
-    function buildPill(option) {
-      var pill = cloneTemplate("pill");
+    const buildPill = (option) => {
+      const pill = cloneTemplate("pill");
       if (!pill) return null;
       pill.setAttribute("data-value", option.value);
       applyData(pill, option.data);
       setLabel(pill, option.label);
       return pill;
-    }
+    };
 
-    function buildHidden(value) {
-      var input = document.createElement("input");
+    const buildHidden = (value) => {
+      const input = document.createElement("input");
       input.type = "hidden";
       input.name = name;
       input.value = value;
       return input;
-    }
+    };
 
     // ── Pill × → remove ──
-    pills.addEventListener("click", function (event) {
-      var removeButton = event.target.closest("[data-pill-remove]");
+    pills.addEventListener("click", (event) => {
+      const removeButton = event.target.closest("[data-pill-remove]");
       if (!removeButton) return;
-      var pill = removeButton.closest("[data-pill]");
+      const pill = removeButton.closest("[data-pill]");
       if (!pill) return;
       if (isFilter) {
         // Filter pills have no hidden input.
@@ -505,86 +536,79 @@
         emitChange(null);
         return;
       }
-      var value = pill.getAttribute("data-value");
+      const value = pill.getAttribute("data-value");
       pill.remove();
-      var hidden = pills.querySelector('input[value="' + cssEscape(value) + '"]');
+      const hidden = pills.querySelector(`input[value="${cssEscape(value)}"]`);
       if (hidden) hidden.remove();
       emitChange(null);
     });
 
-    function currentValues() {
-      return Array.prototype.map.call(
-        pills.querySelectorAll('input[type="hidden"]'),
-        function (input) {
-          return input.value;
-        }
-      );
-    }
+    const currentValues = () => {
+      return Array.from(pills.querySelectorAll('input[type="hidden"]')).map(input => input.value);
+    };
 
-    function emitChange(last) {
-      var values = currentValues();
+    const emitChange = (last) => {
+      const values = currentValues();
       if (syncUrl) syncToUrl(values);
       container.dispatchEvent(
         new CustomEvent("search-select:change", {
           bubbles: true,
-          detail: { name: name, values: values, last: last },
+          detail: { name, values, last },
         })
       );
-    }
+    };
 
-    function syncToUrl(values) {
-      var params = new URLSearchParams(window.location.search);
+    const syncToUrl = (values) => {
+      const params = new URLSearchParams(window.location.search);
       params.delete(name);
-      values.forEach(function (v) {
+      values.forEach(v => {
         params.append(name, v);
       });
-      var qs = params.toString();
-      history.replaceState(null, "", qs ? "?" + qs : window.location.pathname);
-    }
+      const qs = params.toString();
+      history.replaceState(null, "", qs ? `?${qs}` : window.location.pathname);
+    };
 
     // On init, restore from URL params if the server supplied no selected pills.
     if (syncUrl && !pills.querySelector("[data-pill]")) {
-      var initial = new URLSearchParams(window.location.search).getAll(name);
-      initial.forEach(function (v) {
+      const initial = new URLSearchParams(window.location.search).getAll(name);
+      initial.forEach(v => {
         addPill({ value: v, label: v, data: {} });
       });
     }
 
     // ── Close panel on outside click ──
-    document.addEventListener("click", function (event) {
+    document.addEventListener("click", (event) => {
       if (!container.contains(event.target)) hidePanel();
     });
-  }
+  };
 
   /** Minimal escape for use inside an attribute-value selector. */
-  function cssEscape(value) {
-    return String(value).replace(/["\\]/g, "\\$&");
-  }
+  const cssEscape = (value) => String(value).replace(/["\\]/g, "\\$&");
 
   // Serialise each widget's current state onto data-* attributes for the caller.
   // Form widgets expose data-values (the submitted hidden-input values); filter
   // widgets expose data-included / data-excluded / data-modifier for the filter
   // bar to read.
-  window.readSearchSelect = function (form) {
-    form.querySelectorAll("[data-search-select]").forEach(function (container) {
-      var pills = container.querySelector("[data-search-select-pills]");
+  window.readSearchSelect = (form) => {
+    form.querySelectorAll("[data-search-select]").forEach(container => {
+      const pills = container.querySelector("[data-search-select-pills]");
       if (container.getAttribute("data-search-select-mode") === "filter") {
-        var included = [];
-        var excluded = [];
-        var modifier = "";
+        const included = [];
+        const excluded = [];
+        let modifier = "";
         if (pills) {
-          pills.querySelectorAll("[data-pill]").forEach(function (pill) {
-            var pillModifier = pill.getAttribute("data-search-select-modifier");
+          pills.querySelectorAll("[data-pill]").forEach(pill => {
+            const pillModifier = pill.getAttribute("data-search-select-modifier");
             if (pillModifier) {
               modifier = pillModifier;  // last modifier pill wins
               return;                    // skip value extraction for this pill
             }
-            var value = pill.getAttribute("data-value");
-            var label = pill.getAttribute("data-label") || "";
+            const value = pill.getAttribute("data-value");
+            const label = pill.getAttribute("data-label") || "";
             if (pill.getAttribute("data-search-select-type") === "exclude") {
-              excluded.push({id: value, label: label});
+              excluded.push({ id: value, label });
             } else {
-              included.push({id: value, label: label});
+              included.push({ id: value, label });
             }
           });
         }
@@ -594,13 +618,8 @@
         else container.removeAttribute("data-modifier");
         return;
       }
-      var values = pills
-        ? Array.prototype.map.call(
-            pills.querySelectorAll('input[type="hidden"]'),
-            function (input) {
-              return input.value;
-            }
-          )
+      const values = pills
+        ? Array.from(pills.querySelectorAll('input[type="hidden"]')).map(input => input.value)
         : [];
       container.setAttribute("data-values", JSON.stringify(values));
     });
diff --git a/tests/test_search_select.py b/tests/test_search_select.py
index af08ec4..a1bf2ee 100644
--- a/tests/test_search_select.py
+++ b/tests/test_search_select.py
@@ -133,6 +133,15 @@ class SearchSelectComponentTest(unittest.TestCase):
         self.assertLess(options, option_row)
         self.assertLess(option_row, no_results)
 
+    def test_prefetch_attribute_and_defaults(self):
+        # Default prefetch is 0 in SearchSelect
+        html_default = SearchSelect(name="t")
+        self.assertIn('data-prefetch="0"', html_default)
+
+        # Custom prefetch is rendered
+        html_custom = SearchSelect(name="t", prefetch=42)
+        self.assertIn('data-prefetch="42"', html_custom)
+
 
 class FilterSelectComponentTest(unittest.TestCase):
     MODIFIERS = [("NOT_NULL", "(Any)"), ("IS_NULL", "(None)")]