Tilted compass installation

Hi all,

Because I’ve some mechanical limitations, I’m wondering if it is possible to install the Here GPS receiver (2 or 3 models) in a roll-tilted installation, especially for the compass performance?

GPS receiver arrow will still point to the flight direction, but the receiver will be mounted at a constant roll angle of about 20 deg.

Does it compromise the compass performance?

if yes, can it be countified and is there a way to compensate or calibrate this (other than the usual compass calibration)?