Inspired by the progress we are making on Telegram support (thanks @Goldstein !), I found the way we can finally fix Matrix identity verification.
Right now, to verify a Matrix account, one must send a message to a central room (the "doipver" room on matrix.org). It works, Keyoxide.org has no issues verifying these identities. The problem is, if other people want to selfhost Keyoxide and verify these identities, they must create a "bot" account and make it a member of the group. Not bad, not great. Also, this method facilitates scraping. Not great at all.
Suggestion: everyone makes a public room with their fingerprint in the Topic, which can theoretically be queried without the bot being member of the group.
Issues: I think the server needs to support and enable Room Previews. Doing more research.
I think ultimately we'll need to support both methods anyway.
Matrix API request documentation: