Maybe a fediverse platform JUST for accounts? The user page could have a bunch of tabs for each Fediverse platform that account is using.
Now THAT’S a really cool idea. Make one account, let it propagates in any services of your choosing. It would make your presence on the fediverse simpler and more consistent. Add a “share” feature that formats your posts to whatever service, center every communication around your omnipresent account.