@maloki No it wouldn't cause a lot of Federation issues necessarily. It could perhaps cause duplicates, but since #Atom has the "atom:updated" element then - just as with any feed reader - !OStatus implementations can see that it is updated.

However, it should only be possible to update atom:content and not mentions. Categories etc. is debatable.

Why we haven't implemented updates in !GNUsocial is mainly because we solve it the social way, by just saying "oops, made an error" or accept that we are not all perfect and thus can live with spelling errors etc. If it's something really, really bad we just delete the post.

Also, updates are not implemented because I work too much and if I did implement it, I'd want it to have a complete revision history - which would probably be cause enough for people who want to edit their post to choose "delete" instead anyway. ;)