How to get a Gimbal Status?

Ground Control Software MAVLink
1

I have a problem finding a Mavlink message that sends back a gimbal pitch angle to ground station via Mavlink

2

MOUNT_ORIENTATION gives you that

3

Here you said this message is not supported by ardupilot. Has it been added since then?
I also have Alexmos gimbal reporting its orientation through ATTITUDE msg instead of MOUNT_ORIENTATION. And the former doesn’t have yaw_absolute field.
BTW, how yaw_absolute is computed? Or, where is the gimbal’s orientation defined relative to the frame, in case it’s not the standard looking forward orientation?