I've built my own sync engine in rust to run against supabase. It doesn't run the browser though, it's for a native app (tauri in my case). It's column level lww.

I have one place where I'm thinking I might need a crdt due to the complexity of the data and how you collaborate with it.

People take my app offline for long periods of time then reconnect with 1000s of records to sync so my sync is backgrounded and built to deal with several mb of data in sqlite files.

Anyway I'm interested in taking a further look at your thing over the holidays to see if it's worth switching or making partial use of it.