I have evaluated the local first landscape and few solutions are as neat as this one! The only other (more mature seems to be) is tinyBase but that's based on a different model (CRDTs vs Event sourcing)
Few questions:
Would it not be possible to store and rely on larger amount of data on SQLite and keeping it on disk as an option? I see that there's a limitation of 1 GB. So maybe just a config flip to change the mode of persistence?
Also - multi-tenancy could be an interesting scenario. Think JIRA but each organisation needs their own namespace and each user/client wouldn't need all the tickets from all the organisation but only of their own (or even more scoped to department and team) therefore the local database would alway be a subset of the whole universe.
An out of the box sync server that could be run directly on Bun/Node (without Cloudflare) could be a nice addition.
But overall, really elegant solution. I like it, might give it a try in an idea I am evaluating various tools for. Unfortunately, the multi-tenancy story is critical for that.