I would say it's still not at the level where you have a nomadic identity. However, it's better than it is for lemmy (which would involve using an external script to recreate your followed and blocked communities).

So migrating in mastodon is basically recreating your followers (all the people that follow you) in the old account, without external tools. To do this you log in to the new instance, and in account settings there's an option "move from a different account". Then log in to the old instance, and choose "move to a different account".

Then allow it some time to complete this in the background. You can additionally use the export/import options to transfer your follows, lists, blocks, bookmarks, etc. This will probably re-request the people who you follow, so people usually leave a message in both the new and old accounts about how I'm migrating so that they know it's the same person.