Although the CM4 layout appears simple, it requires no specific I/O consideration.

The CM4 is likely to be used by serious users who will incorporate it as a part of a custom system and enclosure. These users will most likely want to source their own heatsinks to match their specific needs. Hence, it may not be worthwhile for RPT to design a heatsink themselves, especially for prototypes and amateur/hobbyist users, as the market may not be large enough. While a third-party may produce one, it is still uncertain if the demand is sufficient for such a product.

Looks like its meant to be set via devicetree. A custom overlay needs to be made for this or the i2c-rtc overlay needs to be altered.

It’s unfortunate that when burning the SD card, one has to choose between the two versions of Pi Zero W. As I use both types of Pi hardware, it would be more convenient to have one SD card image that I can share. Currently, I need to have two separate images and label them accordingly.