The switch panels I described are going to be wall mounted. I see not I did not mention that in my original post. They are going to be about the same size as a standard single gang wall switch plate. I am going to fab these most likely out of wood. Switches are momentary "tact" switches. Not looking to have another "remote" laying around. There are many smartphone apps I could use and I may incorporate that into this also but that isn't the focus at this time.
Using an 8 way relay board won't work because not all lights are separate circuits. That would require a lot of rewiring and tearing up ceilings and walls. Most of the lights are only 2 circuits. I want separate control over about 8 of them.
As for using many ESP-01's, why not? I can put it, a power regulator, the mosfet relay and whatever else is necessary on a very small circuit board for less than the cost of the single wifi relay mentioned. It would also fit in the light fixture too. The songle relay mentioned will not fit into the fixture. Plus I already have all the components to do it.
The reasons I like the mosfet relay is it only takes a brief ground to toggle it. Its a logic level trigger so it can be connected direct to the GPIO. It would require the exact same software command to turn on or off. Plus I can also use a manual switch on the light to do the same thing. Plus the added benefit is I already have them. This is why I would like to use the second GPIO on the -01 module to signal the LEDs on the switch panels to toggle on and off with the relay.
So we have 2 NodeMcu's and a fist full of ESP-01's. Button press on NodeMcu sends the same signal command each time to the appropriate -01 module. Hopefully the relay triggers and then the -01 module senses the change on the other GPIO and sends command to NodeMcu (both) to update the indicator LED next to the button pressed. In this way the LEDs will get updated on the switch panels even if light is switched on manually at the light itself.
Now that I'm thinking about it, seems like it would also be nice to have an "all" button too. One press triggers all on or off.
On the hardware side of the GPIO it may require pull up and or down resistors. Probably "up" on the trigger because ground signal triggers. On the sense side I guess pull "down". I can run the 12v signal through a regulator to 3.3v to trigger the GPIO. It seems to me I read somewhere that the modules have internal pull up/down resistors?
Hope this helps. I still have that beer n pizza $$ for any help on the code. Thanks.