@yab:
It is sufficient to temporariliy disable the zwave-controller “thing” in PaperUI to make the zigbee-stick work as intended. So sure, unplugging the zwave-stick has the same effect. Re-enabling the thing knocks the zigbee-stick out again.
Is that what you meant?
And yes, the USB-ports themselves work fine, it does not matter where which stick is inserted (and shouldn’t).