Yes you can.
I recieved a tailcap board in an AK P7Aurora with tracings for 2 electrical paths. Connecting a 3way switch to this (off / 1 / 2) and a resistor to the 1 path, you get a 2 mode switch.
The tailcap board is easiest to put in a solarfoce L2, modding the surefire tailcaps is apparently a challenge