For anyone who might be running Home Assistant (HA) on their QNAP NAS. You may find yourself looking to access Zigbee devices. There might be a number of reasons you would want to do this e.g. you can replace or never acquire the myriad proprietary hubs that are mandated by various device providers. For me it was because the proprietary support for a PIR device I was using did not emit anything to HA.
Native support for Zigbee gives you direct access to the devices but obviously is a little more bare metal. You also need some way of managing your devices.
The one difficulty I did come across was that even with the USB dongle inserted there was no /dev/ttyUSB0 to be found. After a bit of rummaging I found that device was there but that I needed to install a linux module:
insmod /lib/modules/$(uname -r)/cp210x.ko
The problem with this is that it is not persistent i.e. it needs to be run after each reboot.
I have attempted to resolve this by enabling the "Run user defined processes during startup" option and adding the above command.