Hi I haven’t got one yet, but looking at the heat-trapping structure formed by any pi-hat, I worry a bit about cooling. Pi4 needs a fan even without a hat, and as the hat likely obstructs airflow, fan support seems to become more urgent.
Location: Where do I put that fan? Do I potentially need a new case? Does yours have space for it?
Power: Do I still have a GPIO pin left to power the fan? If not, is there an alternative way to power it?