About the BSFC, off the top of my head I don't see why the constant
    flow nozzles should be at a disadvantage. Maybe at idle, like you
    say but how much time do you spend at idle?

Depends on how long it takes the engine to warm and to taxi out, get in
line, and get into the runway.

Myself, I'm not all that thrilled about the idea of starting my takeoff
roll with wet plugs.

Keith Wood

You do do a run up don't you Keith? :)
If you pull the leaning knob that should clear the plugs when
you do a run up.