Actually, you don't _need_ to sync data, you can send it contextually too https://openfga.dev/docs/interacting/contextual-tuples.

Of course, if you end up sending all data contextually, you are better suited with a different solution that does not require a server roundtrip like Cedar.

This repo compares differences between the OpenFGA approach and the Cedar approach https://github.com/openfga/openfga-cedar-comparison