Over the last few days, I experimented with moving my Twitter archive to my personal #Mastodon account @luca@social.luca.run and finally succeeded.
I had to modify the Mastodon source to allow backdated posts and prevent it from spamming other instances with old posts. Because image descriptions aren't included in the Twitter export, I had to request them from the API. There I got full text for truncated Retweets as well.
Incomplete notes:
https://github.com/lucahammer/fediporter
@osiris @Luca@vis.social @luca@gts.luca.run Exactly, what kind of people create an export for Mastodon but no import ?
Like let people move and just add silent imports or standalone export page of our posts with pics (ecport is directory of pics and 1 big json instead)- we're effectively locked in to 1 instance so pray you instance doesn't go !!