I have all of my open source apps in my main profile, a Shelter profile for proprietary apps (which I hardly use nowadays), a user profile for apps needed for my university, and another user profile for apps needed for a certain gig I’ve been involved with

Buying a domain and using that is a good idea, and you can also do a catch-all so you can give each service their own address and see which ones leak your data

I think they have some sort of critical security flaw regarding spoofing that hasn’t been resolved in years and they had a forum thread about it

I’d go with SimpleX Chat.

Matrix, XMPP, Cwtch are also contenders

In the US, some of the government sites require verification through id.me now

Vanadium for web apps, Cromite with auto delete for random websites, and IronFox with various plugins for web searches