In the end matrix has the issue that federation seems less widely used than it maybe should be. It was a concern I had when looking at it, and when I spoke to the author of conduit (rust matrix server) i made the point that easy deployment should be a primary goal. The existing python server seems non trivial to deploy.

I think that’s still true, I’d you want a distributed setup like that it has to be as close to trivial to setup as possible. Email has shown that complex setups cause centralized solutions.