The use case is local user DuckDB talking to MotherDuck for $.

This is not commercially a terrible idea. Why keep paying Snowflake for bog-standard SQL query workload when SF makes it easy to migrate to Iceberg & commodity engines like MotherDuck?

uh, doing analytics type queries on large datasets that postgres would choke on, as an RPC? I'm using it (ducklake specifically) to build a lakehouse RPC server that can scale horizontally based on resource utilization in k8s.