So, I experimented with running a mastodon instance on another domain. Due to issues with the "cache" directory actually requiring persistence, and thus somehow making all custom emojis 404, I decided to wipe it and try a different fediverse server on that domain. I didn't know about or expect to need to run tootctl self-destruct, so I dropped the database and installed something else. I still have the instance key around, but I realize I should have unsubscribed/deleted all accounts first. Is my other domain now broken permanently for the fediverse? Can I somehow use the extant instance key to unbreak it? I can't find clear documentation of the mastodon cryptosystem, and if it's permanent, this feels like a denial-of-service vector more than a security feature...
The backend especially is not too demanding (thanks to using a compiled binary via Rust). The database demands probably scale, but postgres scaling is relatively well understood. I think right now the least scalable parts look like the frontend node and websocket stuff, but that can be improved. I'm not sure how I feel about Activity Pub protocol wise, it feels pretty chatty, so transit scalability might be something else to consider.