>uBlock Origin's anti-sabotage injections
Do you mean the rules like
*##+js(acis, document.oncontextmenu)
(an example I just added (copied) today)? I've had a lot of trouble figuring out how to make these properly.
>reverse engineering websites and directly using all the internal APIs their own javascripts consume.
Interesting. By userscript or some other way? I've run into a number of situations where I either can't find a pointer to the internal js, or if I do find one, the browser or something ends up preventing me from accessing or modifying internal state with some sort of permission error. The latter might just be React though.
I'd be very interested in looking, if you have open sourced any of this.