@Épine, who is very experienced and mostly edits on a tablet for the Kurdish Wikipedia, has reported what seems to be a quite common problem with mobile editing: Copying more than a couple of words on a mobile device is painful.
In particular, copying whole pages or whole sections (for re-arranging the order of the sections in articles, for merging articles, or for copying a template from enwiki to a smaller wiki) is a common enough use case that I think the team should consider making this be easy. It should not be difficult in any editing environment to open a long section, select all the content, cut it, save it, open a different section on the page, and paste it all back in.
@JKlein (WMF), could you put this on your list of pain points?