I have both an Aeotec V2 hub and a Hubitat C7 hub (both with internal Z-wave and Zigbee radios, obviously). It would be convenient to place them in close proximity (~2’ apart), but I’m wondering if that would create any interference problems?
(They would both be about 6’ from a Unifi Access Point also. That is currently the case for the Hubitat hub and I haven’t noticed any obvious interference with Zigbee.)
Set your two Zigbee radios to different channels, and try not to overlap with your 2.4GHz AP channels. Note that changing the Zigbee channels will cause your devices to go into panic and try and reconnect, could take a few hours for all of them. Some may require re-pairing after the channel change.
Z-wave I’ve had multiple radios near each other and never noticed a big issue. They will step on each other but thats normal in a crowded RF environment.