Re: Derek Roddy here!
I play heel up all the time.
Flat foot is not a "technique" as much.......but, a definition.
What mean is....if I'm sitting at a desk.....and "playing" DB....I run....sitting down.
This makes the entire surface of my foot, hit the ground at the same time (Flat footed).
Now, when you apply that to a pedal (DB pedals have an angle) the motion doesn't change....making the stroke on the pedal...heel up.
Because, the heel of your foot to the bridge of your foot, and then the angle back from the pedalboard....makes a triangle...with your heel off the ground.
All in all...every stroke I play is heel up but, playing from the hip.
I'll take a picture later with my foot on the pedal so you see what I mean.... if it's not clear.