With the vlemmy situation ongoing, i feel like it would be useful to put this here (i did not make either of these tools)
Lemmy Account Settings Instance Migrator (LASIM) copies all your subscribed communities and blocks and lets you upload them to another account, in just a few clicks
lemmy-migrate does the same thing but without a GUI and support for uploading your backup to multiple accounts at once
Hey, author of LASIM here if people have any questions!
Just so people know it does save everything to a JSON file when you click “download” so you can absolutely upload to multiple accounts or keep it as a backup.