How about a very basic mysensor node?

sensor -> domoticz -> mysensor node -> LED

Domoticz has full support for the Mysensors - I use the serial gateway ( as simple as plugging in a USB cable and a 5 line Arduino sketch). https://www.mysensors.org/build/serial_gateway

You don't even need an extra ...

uhh.. no. I don't want to physically change the switch, I want to change how Domoticz sees the switch.

In essence, contribute a new switch type to Domoticz. (Dual push button. i.e. two momentary push buttons)

I found a workaround for the moment - in this forum, there was a person who had asked ...

I've recently purchased one of these switches, and I am able to make Domoticz see it with Zigbee2MQTT plugin.
https://www.aliexpress.com/item/2018-Upgraded-Xiaomi-Aqara-Wireless-Switch-Single-Double-Button-Key-Smart-Light-Control-ZigBee-Version-for/32863511201.html

The double switch is recognized ...

I purchased one of these devices :
https://aeotec.com/small-z-wave-remote-control

Its a tiny remote - with 4 buttons.
It supports short and long click for each of them.

The OZW Control panel correctly recognizes the device and passes it on to Domoticz. (See attachment zwave_device entry)
But in ...