I might just buy one now because I find your wall-power results extremely surprising. My results with basically any mini-PC have been similar between Linux and Windows at minimum idle power; the Windows installs jump up off idle more often but I haven't seen a significant difference in the troughs. The Energy* and other reviews of PN40 indicate ~5W idle, which is more in line with NUCs and everything else I've ever seen from a mini-PC.
The difference between Linux and Windows is almost night and day. On my monster workstation, for example, I have managed to idle it down to 16W (or around 24W with a dGPU. it has alder lake, 6 SSDs in softraid and 128GB of RAM). I never managed to do anything less than 40W in Windows.
> 5W which is more in line with NUCs and everything else I've ever seen from a mini-PC.
Even on this very thread you have been quoted lower numbers. Just search around.