Rather than copy centralised, Integrate useful features across the fediverse
Examples:
Mastodon could use the up down reddit style boost/like buttons
Just giving stylistic differences to services is less important (but end users love it) as it is easier to implement …
Certain aspects are a nightmare of complexity for end users, for example taking followers to new instances should be automatic, then give users the option to unsubscribe, downvote etc
User simplicity is the strength of the centralised twitter, reddit etc … until the content pushing/commercial payback of bubble bursting overvaluations …
I downvoted because I don't understand what you're proposing. Re-inplementing concepts of every systems, like Lemmy, in Mastodon is definitely no-go, that's not the point of federation. I'm not sure what your other point means, are you talking about moving to a new account? And your fourth point is not even phrased like feedback.
This may be a silly idea but I thought a way to be compatible with Mastodon would be presenting a survey interface, with the options Upvote and Downvote.