I have used the Aeotec backup to transfer a network from a non-aeotec (Zooz) controller to an aeotec one.
Have also used the Silabs PC controller NVM backup to copy the Zooz.
There seems to be some limitation/quirk regarding the Zwave library as to what controller can work on the Silabs tool. (I could not use the Silabs copy of the newer Zooz back to the Aeotec or copy the aeotec at all.))
Theoretically, it should be possible to include the spare controller as a secondary controller and then make it the primary controller - but I have no idea how to do that with OH …
I did experiment with that idea but abandoned the project and did not take notes. Check out the aeotec fresh desk on secondary controllers. I think I used the silabs PC controller and pressed the button on the aeotec zstick to include. The backup software worked cleaner as I recall