Do you think it will be possible to find a solution for the H520 ?The steady grip is a simple PWM device. CGO 3, 3+, and probably ET have a legacy port for initialization and tilt movement. No way to pan. Probably the second camera in the ET, because there are two different cameras with a common synchronization and shared memory, should be initialized before use too. Unfortunately, this seems to be done via a serial link from the drone.
I'm watching one grip and probably I'll buy it after the new year. Still, the price is high, let the seller await and take the right decision in the relisting. The idea in the far future is to implement an SR24 inside with some kind of decoder to have full control over the camera.