The time stays at the target location including the time of photo taken(unit: second). For example: the Zenmuse P1 takes about 0.7s to take a photo. If you set stay time with 1s, the gimbal will stay for 0.3s after the camera has finished taking a photo. If the stay time is less than the photo time, the next PathPoint will be executed immediately after the photo is taken.
Euler target angle for yaw (Unit: degree). The yaw angle is relative to the aircraft heading. If you set yaw angle to 0 degree, the direction of the gimbal will be the same as the aircraft heading.
You should use DJIGimbalParamAdjustYaw to get the adjustable yaw range.