@jaredzimmerman well, there isn't gonna be any easily found centralized usage statistics when it comes to the fediverse... that's kinda not how a decentralized network works :)

from personal experience i can tell you that Pleroma (and derivatives like Akkoma) are also very popular and would be easy to add support for, given the API for them is based off the Mastodon API.

Misskey (and derivatives like Foundkey and Calckey) are also rather popular but don't support the Mastodon API, so you'd have to use a different method if that's what you're using