axlns,
I have a QHY8L and experience a similar issue to you, in my case, as soon as I turn the cooler on the power shoots up which does scare the hell out of me too. I usually set whatever the ambient temp is at the time in ‘Set to’ in the module over a time of 2 mins, connect the camera, go over and click Cooler to ‘On’ and hit ‘Set’ immediately.
with an old version of the driver, power would start from 0% and begin rising until SGP’s control system intercepted it and begins bringing it down to 0% again. A newer driver they released used to fire up at as much as 100% which as you said scares the hell out of you.
A long time ago I contacted QHY over the issue and their answer was that on power up, the cooler is set at 50% power (this was the older driver) as they seemed to have the impression that ‘Most’ people, when turning on their camera want it to cool immediately and get to set temp as soon as possible. I requested that they put an option in the driver to apply the 50% power on connection or to have an alternative option to apply 0%, this way, every one will be happy. This obviously fell on dead ears but for the SGP workflow, in my opinion is very important. I like to pre-plan my session and set SGP ready to go way before it is due to start, I want SGP to decide then the cooler is going to turn on and start the cooling process so the camera is cool and ready to go when the sequence fires up.
Although I would normally ‘not’ agree with reverse engineering other peoples software, in this case, after years of frustration with this camera, and the ignorance of QHY over what I think is a simple modification to their driver, good on you for finding a way around the problem.
If I had the money available I have promised myself I will never purchase a QHY camera ever again purely based on their ignorance over this issue, until I have got the cash I am stuck with this camera…Very frustrating for sure 
I’m curious if your modification would also work with my QHY8L, do you think this is possible ?
Many Thanks
Paul