You can do several things to make the boat more comfortable. I agree that numb feet are normally a symptom of bad outfitting somewhere else – either the seat or the hip-pads.
1. Cut out the front pillar so that you have more foot room. I have actually taken the front pillar right out of my last 3 playboats.
2. Either don’t use a foot block, or structure it in such a way that only your heels are supporting weight on it.
3. Make sure your hip-pads are not too tight. If your pelvis can’t spread out naturally, then it can pinch nerves.
4. Move the thighbraces around – I find it helps to have them mounted so that my knees are as high as possible in the boat.
Hope it helps. Good surfing!!