Since it stores the data in SQLite, it would be nice to integrate e.g. ElectricSQL to sync with a self-hosted central Postgres db.
* it doesn't sync with anything but has its own data store, built around sqlite, and you can indeed download "documents", which are just sqlite files. (I looked at how they encode summary tables, and it's not as views, so the grist<->sqlite translation is not as shallow/isomorphic as one might hope)
* authentication is not taken care of by grist-core itself, but they provide different integration methods (saml, forwarded headers, … ?)