This is pretty cool! Some people were asking on another thread about the differences between XMPP and Matrix the other day: first-class support for CRDTs (or equivalent consensus-reaching) is in my view a key property of Matrix and despite not using Matrix for chat yet, i can definitely see myself using it for collaborative apps (Etherpad is still bugged after all these years, and HedgeDoc is in my personal opinion going in the wrong direction by removing explicit macros).

Can't wait for higher-level library (yJS or others) to support a matrix backend so i can mess around with that!