As I know orientation is not so important as it’s corrected while calibrating. Just keep at least 45 deg angels, 90 are better.
I spent some time verifying my orientations and discovered that it is unsolvable.
It’s shown as Y180 what is not a true. Same as your’s.
Compass possition - ArduCopter / Copter 4.6 - ArduPilot Discourse