Random nitter redirect userscript; tested with violentmonkey on brave, gets instance data from https://xnaas.github.io/nitter-instances/

nitter-redirect.userscript.js

// ==UserScript==
// @description Redirects Twitter URLs to nitter
// @name Nitter Redirect
// @namespace Backend
// @downloadURL https://gist.github.com/m0n5t3r/fdd267c81b4e4059a4b409890a019fa3/raw/nitter-redirect.userscript.js
// @include https://twitter.com/*
// @version 1.0
// @run-at document-start
// @inject-into content
// @grant none
// ==/UserScript==

// prevent twitter content from loading
var newDoc = document.implementation.createHTMLDocument (""),
    h1 = document.createElement("h1");

h1.innerText = "Redirecting, please wait...";
newDoc.body.appendChild(h1);

document.replaceChild (document.importNode(newDoc.documentElement, true), document.documentElement);
document.close();

const blacklist = [
];

function find_parameter(name) {
    var result = null,
        tmp = [];
    location.search
        .substr(1)
        .split("&")
        .forEach((item) => {
          tmp = item.split("=");
          if (tmp[0] === name) result = decodeURIComponent(tmp[1]);
        });
    return result;
}

// pick a random instance that is up
fetch("https://raw.githubusercontent.com/xnaas/nitter-instances/master/history/summary.json").then((response) => {
    response.json().then((instances) => {
        var filtered, domain, idx, a;

        console.log(instances);

        filtered = instances.filter((i) => {
            if(blacklist.includes(i.name)) {
                return false;
            }

            return i.status == "up" && i.timeDay <= 500;
        }).map((i) => { return i.name });

        idx = Math.floor(Math.random() * filtered.length);
        domain = filtered[idx];

        a = window.location.href.replace(/twitter\.com/, domain).replace('/shorts/', '/watch?v=');
        window.location.replace(a);

    });
});