Cross-DB permissions

[Dein1]

I have two databases - one is with users and another one is TimescaleDB with time series, connected to the first one as a relationship through Hasura.
Is it possible to use main database tables to set up permissions for Timescale?

I found a way to do this, by querying time series through the relationship, and disable root fields - but this is working way too slow. (5s vs 500ms)

I found a similar issue, but there is still no answer: #8679