I’ve written a tutorial on how to use a USB Z-Wave device as a secondary controller in your SmartThings network to update the firmware of a device. This makes it so you can update the firmware without excluding the device from your network first.
One thing to note when doing an update in place like this is that if new configuration parameters are introduced in the firmware, they may have an unexpected value after the update is complete. It is a good idea to go into the device preferences and set these configuration options to their desired settings to make sure they are set to what you want.