Pixhawk4 IMU and INS performance specs?

The Pixhawk 1 IMU had terrible (or non-existent) yaw angle stability, so we purchased a Pixhawk4 mini. It’s much better and provides stable yaw and presumably pitch and roll.

This is great, but there is surprisingly little documentation on the performance specifications of the (a) IMU or (b) fused INS outputs that have IMU and GPS inputs.

I’ve read all the individual chip datasheets, but there’s nothing that describes performance of the combined IMU or INS system?

Where are the expected performance specifications for orientation, orientation rate, position and associated drifts and drift rates?