@Diane Trout Some of those do change things for mobile clients *a lot* (and iirc telepathy is also used on some non-android mobiles, right?).
@valhalla@identi.ca yes. The Jolla phones and their predecessors use gabble. Someone who had a holds phone did stream resumption patches that need merging https://github.com/noonien-d/telepathy-gabble I think there's also a message carbons, and maybe even some message archive management patches in the GNOME bugzilla