Can’t set parameter 26 (Leading or Failing Edge) to True on Inovelli Blue 2-1 switches

I’m running Home Assistant with ZHA. If I go to one of the switches and hit “Manage Zigbee Device”, then go to Cluster 0xfc31 endpoint 1, then I go to read the leading_or_trailing_edge paramter (0x1a). It returns “Bool.false”, so I set it to “Bool.true” and write. The GUI indicates it wrote successfully, but when I read it back it’s still false. Does anyone know why this won’t go true? The documentation around what set of parameters would keep this from remaining true is unfortunately not all there.

This parameter is intentionally blocked from being changed in Home Assistant (for safety reasons). You can use the tap sequences to change it directly at the switch. Take a look at “Enable Trailing Edge mode” here: Blue Series 2-1 Switch • Button Combinations, Quick Tap Sequences & Local Configuration Options | Inovelli Help Center

For what reason exactly? Why doesn’t the documentation reflect this?

I believe it’s a safety risk. If a light that doesn’t support trailing edge is put into trailing edge mode the switch can overheat. By having the change done at the switch itself, it ensures that the user is keeping at eye on it when making the change and operating on the correct switch.

See Inovelli VZW31-SN Firmware 1.2 New Parameters · Issue #6273 · zwave-js/node-zwave-js · GitHub (red series but same explanation applies to blue)

How do we know which loads are improper?