Interesting. Could be they've never interacted with Lemmy then. I just tried to pull up George Takei's Mastodon account from Lemmy, and no results. (@georgetakei@universeodon.com). I vaguely recall searching for another user in the past (months ago), and they did come up in search. Unless I'm just doing it wrong (always a possibility).

It's not really ideal, but I'm not sure if it can be improved considering the radically different structure of each platform.

Yeah. I don't know what changes would need to be made to Lemmy to support following users. There is a person_follow table in the DB, though, so maybe the framework is there but incomplete?