Userscript that force-unfocusses the currently focused element when you press shift-escape.

force_unfocus.js

// ==UserScript==
// @name         Unfocus
// @namespace    https://clo4.net
// @version      1.0.0
// @description  Unfocuses the current element when you press shift+esc
// @author       github.com/clo4
// @match        *://*/*
// @icon         https://upload.wikimedia.org/wikipedia/commons/d/dc/Escts.jpg
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    document.addEventListener("keydown", (ev) => {
        if (!(ev.key === "Escape" && ev.shiftKey && !ev.ctrlKey && !ev.altKey && !ev.metaKey)) {
            return;
        }

        ev.stopImmediatePropagation();
        ev.preventDefault();

        // activeElement is never null
        document.activeElement.blur();
    });
})();