I'm about to begin a migration from SmartThings, have been reading various posts on how to do so, and have encountered conflicting advice about removing Z-Wave devices. One prominent poster seems to strongly advocate for just turning ST off and doing the exclusion (and inclusion) from HE, which sounds great.
But another post (about 5 years old) says: " it's best to first remove the z-wave devices from the existing net (using ST), from farthest away to nearest. Then add them back (using HE) from nearest to farthest. If you don't remove them first, you may lost the ability to communicate with the most distant devices, resulting in needing to do a device reset to add them back in - which can be really tricky depending on the device."
I'd also read to start including mains-powered devices (to create a mesh for battery powered devices), but the latter post above seems to suggest that it's critical to remove battery powered devices first.
Not sure which advice to follow--have things changed more recently?
Nothing has really changed (except the introduction of Z-Wave LR if you have any such devices and include them that way, in which case the mesh is irrelevant), but I'd suggest following the nearest-to-farthest approach recommended by the second post.
How you exclude them first (to be able to include them on Hubitat) doesn't really matter, and that looks like the main difference between the two posts you found. There are advantages and disadvantages to both of those methods: if you use ST, you'll probably get confirmation that it was that specific device; if you use Hubitat, you'll see an "unknown device" was excluded and should be reasonably sure it was the one you are working on, though there's always the possibility someone nearby happened to put something in exclusion mode (or you if you gave up on a previous device you were working on). There's actually a third method, too, just resetting the device, which (aside from a couple reported oddballs) usually also clears the inclusion data from the device. But if you have access to a Z-Wave controller (or two), I think that's eaiser.
My preference would be to politely remove from ST so it's clear to you what devices you're doing (and have or haven't done), plus if you need to keep using ST as you transition for a bit, you'll at least let that network know about "missing" nodes sooner than it's likely to discover them on its own -- although, of course, you might end up with some devices out of range if you work near to far as would be best for Hubitat.
Absolutely, mains first, starting closest to hub then outward, then battery powered sensors. I did my lock last (only had one at the time).
I did the rip the bandaid off approach, removed everything from SmartThings, then built new mesh on Hubitat.
Check each device as you pair them, look at Z-Wave details and confirm it looks normal, and test it from its Device page. If you have any failed pairing along the way, use the Refresh and Remove buttons on the Z-Wave Details page and re-pair the device.
When I moved from SmartThings, I just factory reset each Zwave device, then paired it to Hubitat. Exclusion is cumbersome and takes too long when you have a lot of devices to move.
I had no concern about "correctly" excluding the device from SmartThings, since that hub was just going to get unplugged and dumped.
I also didn't have any devices connected with security. Those should probably be formally excluded to reset security properly in the device (though even that may not be necessary for all devices). Otherwise, I see no need for exclude.
