RS3 tilt compensation analysis

From your initial post:

You might want to double check EVERYTHING coming from the corrections also? Correct Antenna Height? Same coord system? Physically measure baseline with other methods since short distance?

Also, rule out any excessive RFI or EMF (i.e. high voltage powerlines, welding machines, close by?) even though the new RS3 6DOF IMU may not have a magnetometer to introduce interference?