The biggest thing missing from Mastodon remains the ability to *actually* migrate an account between servers.

The follower-migrate feature is not enough. I need to be able to migrate an entire account, including posts. And I should be able to do it without the former server cooperating (because of course servers can go down). I should be able to get some sort of cryptographic cert I can send to a new server with my posts and they'll be like "oh yeah, this is real, migrating u now".

@mcc the main problem with this is that I could post lots of unwanted content on a server of my choice - perhaps even self hosted - then migrate it to a different server all in one go. repeat this with a bunch of accounts and you end up with a serious moderation headache due to the volume of content appearing in one go inherently bypassing rate limits. there are also DoS considerations, and complexities with handling threads and name collisions post-migration.
@mcc these aren't necessarily hard blockers, but it's definitely a nontrivial system to build so I can fully understand why it doesn't exist yet.