Hey samjs, we've been using Oso at Source.ag for a month or so, and we're really happy with it! Precisely the fact that you solve authorization on a resource level and implement filtering on the DB level, makes it super useful!
The biggest gripe we have, is lack of support for SQLAlchemy 2.0 style queries and lack of support for DB & Python enums as role names
We had a chat with Graham who told us about your upcoming cloud offering. Looking forward to that!