@tombrandis
Thanks a lot for your guide to migrate a matrix account with message history. https://tombrandis.uk/posts/How-to-migrate-Matrix-accounts.html
It's sad that that's the only guide I found; nothing official; and that it's so complicated.
I would like to add details that I stumbled across:
- in the Desktop client, the Button for exporting the E2E room keys is under Setting symbol > All settings > Encryption > Advanced > Encryption details > Export keys
- To try it out, I did the export - import keys after the first chat which successfully showed me old messages. But for the second chat it did not. That worked after another export - import step. So maybe it's best to first do all invitations, then the export - import keys step. Exactly as you wrote.
- you mentioned the step about transferring admin rights. This especially applies to all private 1:1 chats (which I did not notice after I left with the old account). Maybe you could add this info.