The question is, are you looking to use an USB device or an internal serial device on the Yellow pin header?
I’m using an Aeotec Z-Stick Gen5 on a RPi4 BUT this required a hardware mod to fix a manufacturing error (USB D+ pulled-up to 5V rather than 3V3). The Gen5+ has this fixed and can also support S1/S2 security modes. These fixes work on a RPi4, which strongly suggests the very similar hardware of the RPi CM4 will also work.
The other option is to use something like a RaZberry, or Aerotec Z-Pi 7 module which use serial header pins. The RPi4 serial interface causes issues with Bluetooth (shared interface needs remapping), but the CM4 might be different. There were early reports of the Amber case working with the RaZberry connected internally, but I’ve not heard anything definitive since for Yellow. The Pi 7 is also a 700 series interface which has some advantages.
Personally, I moved from a RaZberry to a modified Z-Stick Gen5 as the kit was bought previously, and moving a USB stick is simpler than remapping serial / Bluetooth. I also wonder if having several radios close together is a good idea.
Once more folk have the Yellow, and the CM4 image stabilises, I might move from a 500 to a 700 series Z-Wave device - but then there will be more certainty around physical space in the case, port setup and interference (mentioned again on the 2022-08 release party regarding Bluetooth resets). I’m certainnly going to use a USB 90degree adaptor to get the stick aerial away from the plane of the PCB.
AeoTec were mentioned as working with Nabu Casa / Z-Wave JS on firmware updates, so there might also be a chance of “Works with HASS Yellow” being confirmed.