Sounds interesting. How is Madison handling the funding issue? Are all admins millionaires, living off the stocks they own, so they don’t really care what the server maintenance costs? If admins are just normal people, they probably do care, and in that case, they probably also ask you to donate.
Mastodon has been doing this for a bit longer, so those admins can probably tell you how successful their financial model is. If patreon donations are good enough, then there’s no need to build anything more complicated.