MD600 driver raises a fair point in that a VFR pilot would not necessarily be familiar with any particular instrument approach procedure (nor indeed an instrument pilot for that matter) and therefore a degree of common sense is required when crossing the feathers. Whilst theoretically crossing them at 3000 feet ten miles out or at 600 feet two miles out might pose the same risky strategy, crossing ten miles out at 600 feet poses no IAP risk at all.