Interesting observations Andrew. I have always liked Auto Adapt. For a lot of buildings and the way they are used, the outside temperature isnt always the best indicator of the best water target temperature.
One could spend house drilling into details, and one thing that interests me is this
Its doing what my 6kw Ecodan was doing. I never got a sensible answer at all from Miitsubishi. The lighter ‘overlay’ is Trystans clever theoretical (carnot) COP. Theory, from air source here at 9.5C and flow temp say 35C, is that heat output should be at least 4kW (approx). However, the actual output dips considerably when the input is unchanged. I am certain that your discharge superheat (as ‘running information’ will tell you), drops to zero. Question I dont know the answer to is… whay does it do it sometimes?
We can then look at other times when it doesnt happen
Here, the theopretical COP is about in line with actual.
It would be nice to get to the bottom of this issue.