Best low heat AM4 CPU?

[GoogalyMoogaly]

So I've got a SFF PC that's currently running a ASRock B350 ITX motherboard and a Ryzen 100 CPU.
I believe the CPU is the only thing preventing the PC from being Windows 11 compatible so I'm wondering what options I have as a drop in replacement.
The issue is that with it being a SFF PC in a Silverstone ML08 case there's not much room for a CPU cooler, so I need something that run at least as cool as the 1400. I'm guessing this means a 65W CPU but I'm not sure if all 65W AM4 CPUs hit similar temperatures or if some run cooler than others? I'd expect less core to be cooler but is that the case?

So in short, as the title says, what's the coolest running AM4 CPU (and in the case of a few similar, which is best)?

 

[GoogalyMoogaly]

All of the AM4 motherboards have a 45W "eco" (60W total) setting for all of the AM4 chips of any generation. You will see higher temps on the 5000x series. But in essence they are all cool running if you set them to be in the bios.
On the 6 core chips you will 'lose' about 100mhz on single core performance and 10% on multicore.

The cheapest 2nd hand chip that will run win11 out of the box is the 2600. The bottom AM4 chip with integrated gfx for Win11 is the 3000g.

Oh right, I don't think I've seen that setting, I'll have to have a look.
EDIT: Do you know what the setting will be called?