This new Z-Wave adapter now really makes the minimalistic design of the first-generation Home Assistant Connect ZBT-1 (the official Zigbee and Thread radio adapter previously known as Home Assistant SkyConnect) (in perticular the old “USB stick” form factor platform with the tiny onboard PCB trace antenna on its circuit board) seem very outdated! Indeed, its original form-over-function design was probably a poor choice for a Zigbee Coordinator as that protocol have more inherent obstacles than Z-Wave which makes me wonder if it is not in desperate need of a design update to this new design? 
Though regarding improving the hardware design of the circuit board all type of radio adapters, I am curious if and why it was decided not to add an “RF shield” covering (e.i. an EMF shielding plate cover for electromagnetic shielding / EMI / RF shielding for faraday caging) on top of the Z-Wave radio chip and its components on the PCB?
I have not recieved mine yet so can not confirm that you did not do so but judging by the pictures it looks like has it has a grouning boarder but no metal cover (which is a small metallic enclosure meant to act as faraday cage around sensative circuits):
Now it might in practice work just fine without this but if you aim for this remaining “best-in-class” then it should probably also have a small radio frequency shielding box over the Z-Wave chip as conformal shielding to follow best practices when it comes to electromagnetic shielding too? This is basic design when dealing with radios:
- RF Shielding Tames RFI and EMI Emissions | Masach
- Types, Uses, and Benefits of RF Shielding
- pcb - Basics of board level shielding and grounding - Electrical Engineering Stack Exchange
- What is EMI and RFI Shielding? - everything RF
- Everything you Need to Know about Low-Frequency EMI Shielding - RayPCB
If you look at the Silicon Labs radio modules as a best-practise reference hardware then they usually have a metal cover that normally covers MCU radio chip plus its components and really only explose traces to the antenna (+ GPIO pads/pins):
PS: The only reason why the ZGM230S Z-Wave SiP Module Radio Board does not have it is that it is a development board so its not hardware that should be referenced for production.