Just wanted to chime in with a successful C4 to C8 Zigbee Migration....
That might be a bit misleading because it was a start over more than a migration. I was using the old C4 just as a zigbee radio using hub mesh to sync the devices with a "control" hub that did all my rules. There were but a handful of apps on this C4. Rather than take a backup, restore and "reset" all my zigbee devices, I took this as a chance to just start fresh. Hub mesh makes that pretty easy as once I have the device on the new hub and shared it, I just went into the control hub and changed the "link" to the new device. I did notice that after doing a few of these rebooting both hubs helped everything sync up as sometimes things weren't working as I thought (aka turning a device on and off in the control hub didn't work, but it did from the new C8) after the reboot those issues went away.
The other nice thing about doing it this way was I could do it as fast or slow as I wanted. Just moved a device or two at a time and all the old devices kept working. Mind you I did have the new C8 on a different zigbee channel. But this allowed me to do this over many days rather than trying to get all 80+ devices done in 1 day. Just thought I'd throw this out there as another way to do this migration. Even if your old hub is doing more than just zigbee, you can add a new hub in this manner and slowly move things over.
I've left that C4 running and quite honestly waiting for this exact hub update...the ability to migrate in the future without ever doing this again (I hope). So thanks to @mike.maxwell who came through with exactly what I hoped for....a future migration plan that doesn't include 3 days of my time.
Hubitat has by far been my best investment in my smarthome endeavor.
