the knee moving ahead of the foot seems to be more noticable the lower down from the neck the bar is placed. I accept it as long as the knee is broadly overthe foot ie travelling in the same direction. From what i have seen of tall lifters, expecially ones new to the squat, is their tendency to twist on the assent but the few I spoke to about this found that concentrating on the knee travelling in the direction of the splayed food greatly reduced the twisting force.
As a philosophy to encourage the knee travel in the direction of the foot its useful though when you think of the centreline of gravity its probably unachievable for most of us and not a natural squat position. Bear in mind squatting (not weights though) is or was a normal movement / position for humans until the chair took over. Look at young children when told to sit down, almost all will attempt to tilt the chair forward to an almost squat posture.