Gimbal and control modes


Using v1.14 release, I’m trying to setup px4 to use the gimbal module. We’re trying to have a 2-axis gimbal, doing sweeps for our camera to take picture of an area. First step would be to have the camera pointing down at all time.
I have questions regarding the parameters:
It seems that there is no options to have the autopilot command the gimbal autonomously. MNT_MODE_IN seem to not have autonomous options, meaning the commands can only come from the ground station/RC ?
Secondly, I saw that MNT_MAN_ROLL, MNT_MAN_PITCH and MNT_MAN_YAW only have aux channels as option but when I go see on QGC we can choose MAIN (IO) pins as well for gimbal control. Are there other parameters somewhere in the code that I didn’t see?