The only issue I've encountered was that I wanted to preserve the root domain for my content (instead of Mastodon instance homepage) but didn't have any hosting to perform the webfinger redirect.
Signed-up for Firebase free hosting but it can't easily redirect the .well-known/host-meta URL either so I've hosted it as a static file. Though the documentation wasn't very clear it was possible. I've tried to clarify the content of the file for others:
@ondra glad to help :) Thanks