[Vinnl]

New release with an MVP implementation is now building! It's the opposite of what you described, but should fulfil roughly the same use case: if you select something and then hit the button, it will obfuscate (roughly) just that part of the page.

[KennyBlanken]

Being able to replace via regex or similar would be pretty killer for a lot of streamers who want to guarantee personal info or even usernames never appear on-screen in a browser.