Good morning, @Sven
and GSA pplz...
I don't know that you would want or need to do this. Of course, I expect you to be better able to gauge what is actually worth your time and worth the users' time. So this is just an idea, not really a request.
Right now, I can stop the projects, which then, as I understand, ceases all Active projects from starting new threads and finishes up with all the open threads until zero remain open.
What I considered was just a pause button, which causes a temporary cessation of starting of new threads, while active threads' connections are either kept alive, or allowed to just sit and time out if that's what they do.
Meanwhile, as the active projects sit in pause, either doing (very) little or no work, the user (or task automator - I haven't gotten this far yet!) can do then other stuff, like deal with proxies, or other settings that cause changes when altered on-the-fly.
Finally, the user can then resume, and have the new proxies set up or whatever, without starting again at 1/17000.