1. CE and DU are different.
2. Can't check right now, but (IMHO) the WiFi board in the ST16 has the same IC, where is no Ambarella to drive it.
3. USB port on both PCB and an SD card port is not connected to the mainboard for video processing.
4. CGO-ET IR part is directly connected to the WiFi board.
5. E and A versions are not related to the video.
6. We can change E to A and vice versa. I didn't test this but read for this possibility here.
7. Video chip is obligated to process the video, not to prepare an RSTP stream.
... and so on.
All of these talks here is a processor inside.
If I disconnect the WiFi card fom video card (ribbon cable) it is dead, no WiFi.
This says only about WiFi up after a proper initialization of the whole system.
The target is to use InfiRay T2 Search on the drone. It is a UVC camera with a known set of commands. 26 gram only, 150 meters distance to view. 300 EUR on the second-hand market. The best candidate. Of course, the best will be if the overall thing imitates some known camera for the ST16, and important is to get data from the UART to prepare the right EXIF for every picture, but this is programmatically soluble.
My one should arrive in the next week. I'll prepare a sepparrated topic.