Normally, as most windsurfers, I put front foot first. In overpowered conditions I concider rear foot first to avoid the catapulte feeling when putting front foot first and then lifting backfoot to get in strap. It feels much safer to start with backfoot in hard conditions. Anyway I think it is good to have the choice and I recommend all mediate surfers to learn put back foot first:
If You donīt manage the two possibilities - You donīt have the choice!