Control a Liftmaster Remote LED Light (827LM) locally from outside the MyQ cloud-based ecosystem (e.g. from a Matter Edge driver in a SmartThings hub).
Consider the MyQ intended state of the 827LM when controlling its light smartly.
LiftMaster MyQ Remote Led Light
SONOFF MINI Extreme Wi-Fi Smart Switch with Matter
12V optocoupler isolation module
This is an annotated picture of an 827LM before modifications were made.
Optocoupler isolation module
Remove the 827LM relay (bottom left) that switches live (L → LSW) to the LED light driver (right).
Optionally, you could just disable the relay’s switching ability by cutting the trace between the LSW pads.
Distribute power to the 827LM (L, N).
Distribute power to a SONOFF MINIR4M (L In, N) and connect it (L Out) to the 827LM light switch (LSW).
Distribute power to another SONOFF MINIR4M (L In, N) and control its 3V3 logic external switch (S2, S1) through an optocoupler isolation module (OUT, GND).
Replace the 0805 resistor on the input side of the optocoupler isolation module with one that will work with our 10V trigger (471, 470 Ω).
Drive the optocoupler module (+, -) from what were the 827LM 10V relay coil connections (S2, S1).
Using the eWeLink App, configure this SONOFF MINIR4M’s external Switch Mode to be in Following Mode.
Consider the (MyQ intended) state of the SONOFF MINIR4M when controlling the light smartly with the other MINIR4M.