I can think of at least a couple of dozen fairly technical friends who'd be capable enough to set this up themselves, and who're at least adjacently interested in recreational paranoia. And probably another dozen or two who're definitely into recreational (or possibly delusional and/or fully deserved paranoia) who'd be willing to learn or get help setting this up.

Right now, those circles of friends are _reasonable_ well served with some combination of Mastodon (effectively zero security but with decent findability) and Signal (much more limited mostly to only people you'd be OK with having your phone number).

I will definitely take this for a spin, and start having discussions with particular groups of friends to see it I get any traction.