even better to know! i have the same pedals.

in fact i just received an email back from holdfast:


"We recommend using a BMX-style platform pedal, such as the Animal 'Hamilton'PC, the Crank Brothers 50/50, or the Eastern BMX PC pedals. They also work with most other traditional track and road/touring pedals, just so long as you can thread the lower straps through the pedal along the axle. "


so they work on standard track pedals, but they prefer you use bmx ones.