Mark, both John's of Bleeker and one of the Patsy's locations put the cheese under the sauce. Based on this, and the other coal places listed in this thread, I think it's safe to make the claim that cheese under sauce is a core attribute of NY coal pizza (but definitely NOT a core attribute of the NY slice). Since you're firmly ensconced in a coal bake time and a typical coal level of char, it makes perfect sense for you to gravitate towards a coal approach to cheese.
Now, this being said, I do feel that it's important to point out that, as you and your wife both noticed, sauce on top brings out the flavor in the sauce more. This is very basic physiology. What we perceive as taste is mostly smell, and, whatever is on top of the slice is going to waft back and up to the smell receptors first, and thus have greater impact. There is no free lunch (or dinner) here, if you emphasis the sauce, you're in effect, de-emphasizing
the cheese. For the slice lover that lays awake at night dreaming about properly bubbled WM grande's rich, buttery flavor, this is pretty much blasphemy.
Personal fetishes aside
I think there's a small chance that you might be able to avoid cheese browning while getting good rim color and yet still keep the cheese on top. Didn't the late broil technique give you less browning/more grease on the cheese? Where are you at with hydration? Dropping a point or two could promote browning/rigidity while still not altering your oven spring a great deal. I would also, from a browning perspective, add a bit more sugar and oil to the dough. Other than that, use cold sauce and make sure your cheese is cold as well- and not too finely grated.
You are spending pretty good money on Grande, correct? You might as well try a few workarounds to see what you get before burying it under the sauce and losing all that beautiful flavor (and fat).