I want more POE devices.

It might be that POE power supplies get hot - I've noticed the POE hats for the raspberry pi need a fan

The POE hats for something like a pi convert the high voltage (~48v) down to 5V, so efficiency is going to be generally middling if you don’t spend a lot on the components. I imagine they’re running 80% efficiency or so, which would be an easy 3W of dissipation at peak or so.