Right now IMHO the client that needs desperately the most investment in time and COMMUNITY engineering effort is Conversations.im .
Monocles for example, need someone to implement OMEMO to WebXDC which is the uniquely interesting feature of DeltaChat. Pixelsocial is incredible for in-group private rolls (could literally take the power away from neighbourhood/thematic facebook groups).
Give her a hand! https://codeberg.org/monocles/monocles_chat/issues/353
I'd be happy as fuck to help any of this projects if they were using Kotlin Multiplatform or the RFCs of XMPP were as understandable as NIPs, but they arent