maybe its not the pedal, It could be the fit of your shoe, kind of socks you are wearing or you got your shoe on too loose or too tight.

However, the size of the pedal, the overall contact area (forgot what it is called) is small and can cause problems as you mentioned. If the sole of your shoe isn't super stiff on a speedplay, you will most likely get the hot burning sensation right over the pedal area of your feet. You may need to get a stiffer soled shoes. If you think its stiff enough, I may even try one of the insole inserts some runners use on their shoes to cushion the impact energy. You would have to readjust your seat height and loosent the straps on your shoes if you try the insert.

Try few other things before you give up on the light action pedals. It is a very nice pair of pedals.

Smilingcat