I've made the migration of @maou to my #gts instance and used #slurp (a tool from @vyr - https://github.com/VyrCossont/slurp) to try to not loose all the nice toots that have been posted in past years.
522 of 2908 toots have been migrated 
For what I understood, only a subset of posts can be migrated: top-level public posts that doesn't include other accounts.
It makes sense, but I have the feeling to loose a part of @maou's history 
Also, it seems 906 of 1180 followers have been informed of the move; I'm not sure how the moving information works but I've the feeling there's always some followers lost in this kind of operation. Or may be, it just takes a long time to contact all servers and I have to wait few days...? 




