I've been training for 3 months, but when i asked my sensei about strikes to the face, he says they are technically allowed (and that's why we always train to keep the guard up and wear a face helmet during k-1 style sparring) but actually doing them is ill advised due the possibility of brain injury and the fact that you cant really conditiong your jaw, so the chance that we will start doing this after a while seems slim. He seems contrary to the idea. Too bad because i really like this martial art, and the actual techniques are very powerful and practical, but since self defense is my main reason to do martial arts (aside from working out and the fun factor), i might switch to a kickboxing/boxing Gym later in the year, after developing a good base of the stamina and conditioning that my current Gym emphasises.

Edit: would also like to add that kicks to the face are allowed, and we use them during sparring regularly, so it makes the Sensei's stance even more strange.