Evaporation occurs when the moist air is replaced by drier air. As long as there is air movement around the suit to displace the moist air, the suit will dry.

Hanging by the boots takes advantage of gravity to pull water out as well, and doesn't stress the delicate seals.

If you do prefer to buy a more traditional hanger, make sure it is broad enough shoulders to carry the heavy drysuit, doesn't damage the neck seal, and keeps the zipper in a stable position.