MP,
My comfort zone with sharing knowledge and experience, having endured the D1process with a son, is with pitching but I will go out on a limb and share this. S.O. is absolutely correct in what he said about coaches recruiting "up the middle" first, then SSs second only to Pitchers, they are usually the most athletic players and can simply be moved anywhere on the college field. I heard one D1 HC say once, "every position player on our roster was the starting SS for their HS team."
I don't believe you said if your son bats Right or Left? I believe Left-side hitting CIFs are more desirable and therefore recruited sooner than RHBs. Not a rule, just a tendency.
What caught my eye in your description was referring to your son as "bulky." Bulky as a sophomore can turn into "chunky" summer before Sr. year if not monitored. Often CIFs in HS are there as they do not have the speed and movement of a spry MIF. I'm sure you know this. S.O. is correct also in saying, "Bats play." But that bat better be off the charts, freakish, and consistent if the feet don't move faster than 7.4. Going from a 7.6 to a more attractive 7.2 is no small feet (no pun intended), and it needs to get done asap for D1 consideration. And the glove needs to be equally consistent. I know for a fact there comes a point where a D1 RC will say, "We love his bat, just don't know where to play him in the field?"
My thought is a desirable CIF should be more linebacker than lineman. That's my caveat. If he's "bulky" as in linebacker? He should be fine. But if he's trending toward lineman? That may be an issue for recruitment as a D1 CIF.
Hope this helps.