@emile that would be very interesting. @arj I'd definitely like to hear your insights.
As a random aside, #briar (homepage) is a distributed IM that has a Tor node built in. Every client runs an onion service and all Internet communication runs over the Tor network.
Tor for scuttlebutt definitely works. There is even a page in the handbook about it. When I was working on patchbay there was a switch to only connect to tor pubs. That being said I havn't touched that for a while so it might or might not work atm ;-)
In general I'm not really a super fan of just saying run over tor and now you are safe. Like there are also things like exif stripping (also works in some clients) that needs to be considered, the UI in general needs to be focused on the security aspect. Private groups and rooms 2 (with privacy) would also fall into the category of good candidates for a security focused SSB client, so that was what I would focus on if I were to work more in that area.