You cannot turn it off. Not sure why you would want to go to DeConz though a lot are trying to get off of it.
I started with a HUSBZB-1 and went to Aeotec for my Z-Wave and a ConBee-1 for Zigbee. I use the Native ZHA integration not DeConz and am happy with it. I really don’t know that it did a whole lot other than I think the ZigBee range may be a little better. Cree light bulbs that were fine on the HUSBZB-1 didn’t care for the ConBee but that is the only issue I have found, not sure how the ConBee-2 is.
The big thing is getting the Zigbee and WiFi channels away from each other. I didn’t find out about this until I went to the ConBee-1 so in reality getting off the HUSBZB-1 may have done nothing for me other than separate my Z-Wave and Zigbee. I did a write up on the radio interference that may help you if you have issues with connectivity and speed at this link…
Just my 2 cents from what I have found playing around…
Almost forgot… I too still occasionally lose a ZigBee device but rarely since I fixed the radio interference issues.