> our friends at Bluesky announced their application protocol for building decentralised social media called AT. While not based on Matrix, there are some parallels, and some stuff we may be able to get inspiration from around portable identity :) https://blueskyweb.xyz/blog/10-18-2022-the-at-protocol

Sounds like some there are some parallels, and the protocol might inspire portable account identities in Matrix!

The only account migration tool I know of at the moment is proprietary [1], I'd love to see portable identity in Matrix come to life.

[1]: https://ems.element.io/tools/matrix-migration