That’s a lot of words for it’s the same concept as using any oAuth (Google signin, Facebook, etc.) Does Google control that random site that lets you use your credentials to sign up, nope it’s just an accepted method people agreed to. Replace oAuth with lemmy and each site adopting the method to talk they just can, but don’t always talk to each other too.
Welcome to really old technology, again the Usenet
Don’t know you, but you’re a tireless worker who goes as above and beyond. You’ve always been there when needed whether it was helping me understand that new online ordering stuff with COVID or just mowing my lawn when you were younger. I would definitely love to have someone like you as an employee. Send them my way
Either tailscale the network and not worry about it being “public facing” or if it must be somewhere in the denizens then an outbound only connection between a secure remote server and my server.
Eh this is the same fad with probably the same people who all bought/would have bought a Mustang in the 90s