Meanwhile I'm still trying to understand wht the bounty tag for threads is a problem. It seems to be the most obvious solution to this whole thing, and is available already. Setup the thread with that tage and specify in the title that other interactions are welcome as background flavor. Or even trying to stop the hunter at the risk of becoming hunted.
In this case I would say if a player with their toggle off joins the thread and tries to interfere in the capture, then hey, you are fair game now until that thread ends. And if it's part of a series? Great you just signed up for that hunter to pursue you in the associated bounty threads.
Overall the whole thing just seems like its getting too bogged down in rules. If we gotta have em, make em, but really on a collaborative board it should boil down to simple DM's or discord messages.