Schematic for CM4 IoT Router Carrier Board Mini

Does anyone know the best way to cool a Raspberry Pi 4 when it's crammed into a small enclosure? I've found those tiny stick-on heatsinks are surprisingly effective when combined with a small, quiet fan. Have you tried something different?

This would be great…  I'm trying to figure out what the difference is between the RPi 4 LEDs and the Router Carrier Board LEDs.