Yes, it is legal to turn left towards Heraklion (and Lidl!). However, as they still have yet to finish surfacing the road, exercise a bit of care. The problem is that cars approaching from Aghios are supposed to stop at the white line and wait, not commence their left turn. However, most Greek drivers turn into the centre of the highway and you are never sure whether they are going to pass to your left (correct) or your right! >:(
Champion (or Marinopoulos as it is known locally) opened last September.