Does it support filtering though?

Edit: post filtering only

I don't understand how people are efficiently implementing tenant/user/permission scopes with these indexes.

Checks notes, one dayabase per client, per user, per project ... etc

Partitioning is the easy bit I think, and falls out naturally from Postgres.

But how are people doing recency biasing with vector databases?

All of our approaches are either expensive or super hacky.

Multi-column indexes for multi-tenant tables is planned for a future release.

LanceDB supports push down and list/array membership through DataFusion.