It’s not free, but check out Hermit. It’s the best sandbox app I’ve used and I use it daily. It creates “applets” that are basically icons on your desktop that launch the sandbox instance. So I’ve got several I use daily: wordle (and variations), a forum I frequent often, different web comics, etc. No need for an actual app installed for each of those when I just have a single app that creates small instances
I literally just started doing that.
Trying to be active in communities and filtering out communities and domains I don’t want. That way it’s sort of a reverse curated list. Not communities I selected to view, but everything except the ones I don’t want to view.