Here is a second set of testresults. I took a sequence of darkframes with EZcap. Settings gain:10 offset:100
I waited for the temperature to stabilize. Here is what I found from left to right top to bottom.
240 sec, 120 sec, 60 sec, 0sec, 5 sec and finally another 120 sec.
as you can see 240sec has an average of 412 versus 470 for 120 sec. Again reversed from what you expect. If what you are suggesting is correct, the chip was cooler during the first 240sec. The 60 sec is 412 again lower than 120 sec but same as the 240. then 0 seconds is higher again at 487! so highest so far! The 5 sec follows at value 401 lowest so far and much lower than the 0seconds. Finally the 120 seconds again and now at 412 or about the same as 240 and 60 seconds earlier.
There seems to be no consistency here as far as I can tell.
I am curious as to what you can come up with.