the best place to ask questions about Yrs is in the discourse chat.
Yjs & Yjs are compatible. They can communicate updates with each other and they expose a very similar API (as compatible as possible). The Ywasm port (based on Yrs) exposes an API almost identical to Yjs. There is even a y-websocket compatible backend and client implementation: yrs-warp — WebSocket library in Rust // Lib.rs