You can already do this with deconz, I’m doing it like this in my dev setup. It’s pretty simple, attach the conbee to the pi, install the deconz software, use the ip of the pi when configuring the deconz integration for Home Assistant, profit.
You can also do USB-over-ip. You could also install Home Assistant on the Pi with the USB stick and connect the instances throug mqtt statestream/
eventstream or home-assistant-remote.