Seems like this is working for my use-case:

function debounce(func, timeout = 100) {
  let timer;
  return (...args) => {
    clearTimeout(timer);
    timer = setTimeout(() => {
      func.apply(this, args);
    }, timeout);
  };
}

/**
 * A hook used to keep the scroll position of elements
 * inside a sticky liveview after a live navigation.
 */

/**
 * Session storage key for restoring panel size.
 */
const SCROLL_POSITION_STORAGE_KEY = "scroll-position";

const KeepScrollPosition = {
  restoreScrollPosition(_info) {
    scrollTop = sessionStorage.getItem(`${this.el.id}-${SCROLL_POSITION_STORAGE_KEY}`);
    if (scrollTop) {
      this.el.scrollTop = scrollTop;
    }
  },

  mounted() {
    const save = debounce(() => {
      sessionStorage.setItem(`${this.el.id}-${SCROLL_POSITION_STORAGE_KEY}`, this.el.scrollTop);
    });

    this._restoreScrollPosition = this.restoreScrollPosition.bind(this);
    this.el.addEventListener("scroll", save);
    window.addEventListener("phx:page-loading-stop", this._restoreScrollPosition);
  },

  destroyed() {
    window.removeEventListener("phx:page-loading-stop", this._restoreScrollPosition);
  },
};

export { KeepScrollPosition };