Oh definitely that the next couple of weeks will be spent preparing for a new wave. I wouldn't be surprised if that was the reason why Lemmy.ml was down. Yes I know that it was because of a server migration but, that server migration also didn't happen for no reason ;-)

The first migration wave to Mastodon was very bad. I still remember, that following a person was nearly impossible. Not to mention the fact that, even if you could follow someone, it didn't automatically meant their messages ended up in your feed.

I know for example that version 0.17.4 of Lemmy (that was released 2 days ago) already has some database optimizations.