I only use Grande 50/50 (50% 100%low moisture whole milk/50% provolone)
I par bake my crusts on a pan daily and shelve them, dress the par baked crust and cook the pizza on a pan for 8 minutes and the off the pan directly on the stone for 2 minutes, all in stone lined baker's pride ovens at 450 deg.
The result is a thin, crispy, crust NY style pizza that's the talk of my central TX town!!...BUT...the GRANDE cheese won't brown. If you overcook a pizza, or even leave it in for 15 minutes.....it still doesn't brown. They tell me that's the test for quality cheese (it's at 3 bucks a pound now).
Maybe your cheese is a high quality and it won't brown!! The grande just kinda milks up if overcooked and then comes back together when it cools. Now don't get me wrong, I never tried to cook just the cheese for say 20 minutes and make it brown, but I do know that at 450 deg for 15 min., it doesn't.
Grande sends you all kinds of table hats, wall art, window stickers, box stickers, etc. that all say stuff like "the difference in a pizzeria and a pizza chain is the cheese" etc. and we just tell everyone that the quality cheese doesn't brown and they love it!! If you never tried Grande you should, it is an awsome tasting cheese!!
Hope this helps!!