I see huge untapped potential for webxdc apps if some improvements are made

Hey, I’m glad you’re liking WebXDC!

Indeed, I also think that this is quite a big problem, at least in Delta Chat, at least hypothetically.
Although I don’t recall anyone noticing this happen in practice.
Our most recent “advancement” on this front is recommending that apps send the whole CRDT document (Yjs or whatever) state with each message:

See Above group-level Webxdcs / Aggregator Webxdcs.