C-GO3 Is CGO3+ for Typhoon H compatible with Q500?

Not really.
You were probably already aware the YAW control will not work. But the Pitch(tilt) control will not work either. The camera will stabilize and only point straight ahead and level all the time.
The video will probably display to some degree but it is very likely to be broken up and have a serious time lag. How bad depends on which firmware versions are loaded on the camera and on the controller.
The camera is also too tall and will rest on the ground when mounted on the Q500.