Many forums and other discussions point out that the Raspberry Pi 4 can run very hot.
I am sharing here something I am looking into that is not ideal but is compatible with mounting on the Pi4 and still have the Pi4 be able to be mounted on our MCB main board.
Consider this a suggestion and maybe others could try it and offer feedback.
All fans of course go bad someday so there is a reliability issue with any moving part but I wanted to share this as ‘food for thought and consideration’
You mount the fan so the red and black power leads can reach our jack labeled ‘JTAG201’. Red to the VCC pin and black to the GND pin.
It must be a 5V fan so check tht if you get a different version as I have seen these on Amazon but each is a bit different. The one I show is short enough to fit others may not fit. Watch the height.