While working the nFrame, using the focuser/nstep.cpp driver as a base, I found a one line bug in the nstep.cpp
Namely the 'name' of the Coil's switch for energized 'on'.

    IUFillSwitch(&CoilStatusS[COIL_ENERGIZED_OFF], "COIL_ENERGIZED_OFF", "De-energized", ISS_OFF);
->>>    IUFillSwitch(&CoilStatusS[COIL_ENERGIZED_ON], "COIL_ENERGIZED_OFF", "Energized", ISS_OFF);
"../focuser/nstep.cpp" line 91 of 798 --11%-- col 31

Should be 
    IUFillSwitch(&CoilStatusS[COIL_ENERGIZED_ON], "COIL_ENERGIZED_ON", "Energized", ISS_OFF);

The implications of this are that the coil's can never be left energized after a move

Good catch! Fixed.