Kinds of Zigbee Dongles

Zigbee dongles you specified are hard to find (conbee II) or not very performing (Digi XStick)

What kind of firmware have these dongles ?
Are they simple packet sniffer ?
May we try to use other Zigbee sniffer dongles .

The Zigbee adapter has a concept of drivers, such that it can work with multiple dongle types.

With that said, if there are other dongle types you would like support for, you could either write a driver yourself or open an issue on the add-on’s repository: https://github.com/mozilla-iot/zigbee-adapter/issues

The dongles are much more than simple packet sniffers. They also perform the role of the Zigbee coordinator, which is a non-trivial piece of software.