I used to have 3 dumb switches controlling 1 physical light, 2 of those were 3-way switches and the one physically in the middle was a 4-way switch. I did not want to end up with one smart switch so I replaced all 3 with the Inovelli switches, my understanding from these forums was this was possible however the wiring would not be the same (this is not a question regarding wiring.)
To accomplish this, only one switch (the one wired to the light) is actually controlling a load, the other two switches are only powered (via line/neutral) and do not connect to anything via their load terminals.
I created a group in ZHA and if I issue commands directly to that group entity it is reflected by all 3 switches, however, none of the switches (or the group) react to any local/physical actions of the other switches.
What do I need to do so that any actions (on/off/dimming) done on one of the 3 switches are reflected on all 3 of the switches (or the ZHA group of the 3 switches.)
I have used Zigbee binding with a Blue Switch and 3 Smart+ bulbs-all on Hubitat, and you could very well do the same with HA, although I don’t understand enough about HA to advise you how to do, although there should be something on Youtube for Zigbee binding in HA.
With Zigbee binding all 3 switches together, which would allow all 3 switches to function together, even when the HA instance is down, as the switches would communicate directly with each other.
I typically don’t use groups only because I had some issues with it early on when I was getting some other devices set up, but binding the switches individually to each other has worked flawlessly for me in ZHA.
Go to devices → Zigbee coordinator “Devices” → Switch 1
Under the device info box click the three vertical dots and select “Manage Zigbee Device”
Select the bindings tab, then use the “Bindable Devices” box to Bind Switch 1 to Switch 2, then repeat the process for binding to Switch 3.
Bind switch 2 to switch 1 and 3, then bind Switch 3 to switch 1 and 2.
Done! It’s a little bit of a pain over using groups but like I said, I haven’t had a single issue in both 3 and 4 way situations.