I had another look at the characteristics of the fan protocol.
Lamp and fan are each being switched with a single pushbutton, so no separate buttons for on and off.
If we would make a protocol based on normal (stateful) switches, ofc we can let the protocol send the same codes for on and off, and toggle between states when the remote is being used, but that would have a big disadvantage. If the state of the device in pilight gets out of sync with the physical device, there would be no way to correct that from pilight like we can do with a normal switch (by switching back and forth once).
Only if we would leave out receiving capability from the protocol, the remote could be used to bring the state of the physical device back in sync with pilight.
So imho using normal switches wouldn't be a good idea. The fan protocol will require stateless switches ("pushbuttons") instead. Forgive me if I am wrong, but as far as I know there is no such hardware type within pilight yet. I am sorry, but developing such a thing would be beyond my capabilities now, apart from the lack of time