Thanks for the detailed reply.
I'll give that a go - switching over my c4 and c5 so that the bulk of the network is running through the C5.
There is another thread on here - this one:
Where people have been able to upgrade the firmware on their nortek stick, and then are able to do a proper native NVM backup of it. If Hubitat also allowed manually uploading an NVM backup it would be possible in theory to restore that backup to the Z-wave chip in the C7.. thereby enabling people to move from C4/C5 --> C7 without repairing all of. their devices... which can be impractical
