I'm glad that you were able to get some images out off it!
I started to implement binning and then put that on hold. I just double checked and see that the driver is still advertising binning support, which was not what I intended. Binning could be added without a lot of effort, but I wondered how valuable that would actually be given that the sensor is small and the pixels are already pretty large. But, someone who's motivated could do it Subframing is also not supported by the driver, but we understand enough of the camera control protocol that it could be.
I believe that the cooling is a setpoint-style interface. That is, the driver tells the camera the desired temperature and the camera is responsible for adjusting peltier power and fan speed to achieve the desired set point. The G3 hardware can only cool down to ~10c below ambient. If you set the cooling to something like 5C below ambient I would expect that you would see the power spike and then decrease as it reaches the setpoint and maybe settle somewhere around 50% (+/- 20%). You could also try experimenting with cooling in the orion capture studio and see if you see the same power/fan behavior. I suspect that the fan is controlled by the uC on the camera rather than through the driver. At least, that's what I would do if I designed the camera. Also, I don't think there were any write commands whose function wasn't figured out.
I would love to see what you were able to image with the camera!