Just want to clarify here, I think Kenfuhr was originally asking about a Z-Wave switch that uses mmwave radar for presence detection instead of PIR (passive infra red). Supposedly mmwave has the potential to work better at detecting stationary people, for example someone working at a desk or reclining on a sofa.
I personally would be very interested in a version of the ZEN12 with a mmwave sensor, I hope something is in the works!
Weāre looking into mmWave technology but we need to make sure that detection can be fine tuned to our most popular use cases since there have been issues reported with pet immunity, etc. I agree that mmWave has great potential and weāre definitely watching it closely. I hope weāll be able to announce a product that leverages it in the near future 
Somewhere I read about PIR being quicker to sense someone entering a room, yet mmWave is better at sensing room occupancy. If thatās a valid assumption, one could surmise a combo device would be a superior solution for the common case of, āturn on the lights when I enter the room and leave them on until (sometime after) I leave.ā Perhaps more expensive, perhaps only a niche device? Itās really a marketing decision on cost vs. benefit vs. reliability (including pet immunity). If it makes sense at some point, Iām pretty confident @Agnes and the Zooz team will be looking at such a solution, considering the rich line of Z-Wave products they offer! 
I have pitced to them earlier that they should make a cilingmounted motion/presence sensor 
But with mainspower. Knx got this and it is nice
Example what i want:
Mains powered
ciling mounted
Pir detection for motion
MM wave for Presence
Temperature sensor
Lux Sensor
1 input for external temp (maybe one can have external temp sensor like the NTC 10k ohm type)
2 digital inputs for buttons (1x, 2x,3x, hold and release function)
This would have been my number one device to go to in all rooms of a house
So, admittedly Iām an mmWave novice, but I have three different mmWave sensors Iāve been intending to start testing ā¦ All zigbee at the moment. The 24Ghz and 5Ghz Iāve had setup in two different locations, and the third is a LinknLink (60Ghz?) that is still in the box.
My experience so far is that they do a great job at detecting when presence starts, and a āfairā job at indicating when presence is maintained, but they still do report no presence even when someone is sitting right in front of it. Iāve coded around this in home assistant to require a sustained amount of no presence time before taking any action (like turning off a light, etc) but they seem far from perfect.
However the amount of motion needed for the mmWave to tell you are still there is far lower than getting a PIR to know you are still there in my experience.
What I really want to test is the ability for it to know and react to specifics about the thing being present - like only react when the person is over 4 feet tall (to eliminate my dog from triggering, for instanceā¦ as long as he isnāt on his hind legs LOL). I can calibrate the distance from the sensor to trigger which does work fairly well. I actually bought the linknlink for the ability to map out a room and have it trigger differently depending on where a person is in the space of the room - all with one sensor device. But Iām not there yet.
Anyway - the only point of this comment is just to say mmWave seems better but far from perfection; at least with the gear Iām playing with.
Also the units I currently have are USB powered with the connector at the bottom, which to me is just not aesthetically pleasing in a home environment. These need to have maybe 12v power connectors or be the form factor of a light switch for a better looking installation. I despise USB powered for anything that needs to be visibleā¦ and certainly donāt want to ever see wires hanging, etc.
Thatās what Iāve read, as wellābut no experience with mmWave myself yet.
Pet immunity isnāt a big deal for me, but understandable from a product viability standpoint. Ya gotta have it! 
Totally agree! USB power is convenient and can be done by almost anyone without damage to the device. But it is kind of ugly! 
The Zooz ZSE70 800LR Outdoor Motion/Temperature/Lux sensor is a nice example of non-USB external power, but not everyone is handy enough to wire up external power. (Alas, mine is still in the box and I still need to install it outdoors.)
The (older) Aeotec Multisensor 6 had a ceiling mount, although I never tried it. I believe it may still be available for the later Multisensor 7 & 8 devices. But, again, it is battery or USB powered. How someone would power a device like this buried in the ceiling with USB and still remain compliant with their local electrical code is an interesting discussion in itself. It would be so much easier with a mounting kit designed to fit a standard ceiling mount electrical box that includes a line-powered power supply with a USB pigtail to power the device! 
Iām an advocate of using PIR for quick initial detection and then using mmW for ongoing in-room detection (at least in tricky areas like a bathroom shower), but I donāt believe a single combo PIR/mmW device is the right way to goā¦
The main issue is that both PIR and mmW have similar FOVs, so while the initial detection advantage of PIR may still exist theoretically, the reality is that it becomes more of a wash when both sensors are oriented the same way.
In our bathroom, I use a PIR sensor positioned exclusively to catch you as you cross the plane of the doorway, so the light comes on immediately. Then the Inovelli mmW switch (which faces into the room) takes over to keep lights on. If I used a combo unit in the mmW switchās current position, then that initial lightās-on would be delayed noticeably simply because it take a couple steps inside the space to get into the sensorās FOV (mmW or PIR).
Edit ā I realize now I approached my response here from the lens of the combo device being a wall switch (or a device mounted at that approximate ālevelā)ā¦ If you were to mount the combo device in ceiling, or at least higher up on a wall so its FOVs could be canted down to āseeā more, then Iād agree that such a device can make better sense.