I’ll probably pass on updating the firmware if I continue to have success adding them to Home Assistant. Upgrade 15+ devices isn’t really in the budget right now if functional.
It looks like most of my switches are nzw31T. I thought it was NZW31s as they supported scenes. Most look to be running Firmware 1.3.
Nice, the toggle switches? Those bring back some memories 
I think we only made like 1000 of each total. Very limited edition!
Good news is those should have the latest firmware on them - the firmware is equivalent to the NZW30-S and NZW31-S.