I wouldn't exactly say mbin is behind kbin, as things have diverged much since the fork. For example, mbin has moderators from lemmy, and lemmy shows mbin moderators. As of latest, mbin gets moderator reports from lemmy (and maybe the other way, I didn't closely review that PR), things like sensitive groups are marked correctly, subscriber and follower counts come from source... Still, there's a lot of work to do for the user experience, many people have made that clear lately, so I'm hoping mbin will be able to gain the contributors needed to make the changes people want to see

Also, yea a lot of /kbin tweaks won't work. I do want to make an eye toggle button to make visible all nsfw on a page, but that might be hindered a bit due to infinite scroll (as well as a user setting to just have it shown by default). In the meantime though, it's just the structure of data changing from javascript to css, so it's always possible to do. I wrote a tampermonkey script able to do so as an example:

// ==UserScript==
// @name         Mbin tweak
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Unhide NSFW entries automatically
// @match        https://fedia.io/*
// @require      https://greasyfork.org/scripts/12228/code/setMutationHandler.js
// ==/UserScript==

checkThem([].slice.call(document.querySelectorAll('input[type="checkbox"].sensitive-state')));

setMutationHandler(document, 'input[type="checkbox"].sensitive-state', checkThem);

function checkThem(nodes) {
    nodes.forEach(function(n) { n.checked = true });
}

based on this answer on how to check all checkboxes on a page