AJ had 8 QB hurries and 4.5 sacks as a true freshman ... and that is without him really being that good against the run yet. Furthermore, as you and others point out ... since he's young, he wore down faster than our veterans because of issues of technique and functional strength.
Thus, there are many very exciting gains to be had by AJ. As he understands the D better ... his reads will be better and faster as it relates to recognizing run versus pass. That will help him become a better every-down player for us. This, in itself, will cause him to see the field more.
Furthermore, as he gains functional strength and continues to improve his technique ... it will take longer for him to wear down ... AND he'll beat the guy trying to block him with even greater frequency! These features will make it harder for him to get OFF the field (because the drop-off between him and the next guy will be even more pronounced).
Part of his development in terms of size will likely center more about the retention of his speed and athleticism .... thus, I could see the coaches having him be at a playing weight at DE comparable to Clayborn's (ball-park of 285 to 290).