Excellent work Brendan
Regarding testing of the camera with missing sensor, here is an interesting observation I made last night:
I pulled out my 2nd board to do TEC testing and noticed that the 5V regulator was hotter than the 3.3V regulator, unlike my 1st board. After a while I realised that it did not have a sensor and after inserting it the 5V regulator got cooler than the 3.3V regulator, as it should be.
Interestingly the total power consumption was 210mA with a sensor and 190mA without a sensor. However, although the total current was less, the heat production was higher without the sensor, especially on the 5V regulator, like the power "got redirected" to a "wrong" place heating components that are usually not that hot.