Wow this is excellent, I wish bangs were part of the web spec and all browsers supported it client side. It could work like unlock origin and its filter lists so the websites aren’t coupled and instead are dynamic.
Exactly, there’s so much potential beyond search. Bangs could act as general browser-side shortcuts to deep links, so something like !ghsettings could take you directly to GitHub’s settings instead of making you do this manual navigation through the site you are visiting