Welcome to the Hide rum. Not quite sure what you're asking, are you asking if anyone has tried a "low" mount with a flat top AR before? Part of the reason folks don't opt for a low profile mount (of which they are hard to find, I think GG&G makes the lowest and AD also has a pretty low one) is the fact that with a standard stock and proper cheek weld you're right around 1.45 - 1.50" from top of picatinny rail to center of scope, so if you get a mount within this range you should be just right. If you get a mount that is "lower" then your center may be off from your eye position which is going to cause issues with getting a clear sight picture. There is no "need" to have the scope mounted as low as possible with a flattop AR, it is better to get a mount that places your scope in the proper position to get a clean sight picture when you bring the rifle up to your natural hold.
