Hows that?
A possible method to do it w/o the inner current path: it’s powered all the time and a circuit in the switch cuts power temporarily when the E-switch is pressed and the FW runs based off the length / number of power interrupts.
I miss my Nitecore D10 but now I can’t wait for the fw3a (this things m/o, whatever it may be, won’t compare with the inner current path method)!