If it is true CQB just use the scope as a big ghost ring or for that matter point shoot. Try this excersize at 3 5 7 10yards on an IDPA type target.
2-3 rounds as fast as possible to center mass from a low ready position. At the closest distance the target will fill up the scope. Think of it as a caveman Eotech. In every cqb rifle class I make guys run their guns with the optics turned off. Most can get hits to 25 yards without iron sights just using the scope tube as a sight. In CQB you also have to be aware of the sight offset. on a standard AR it is around 2 " with a red dot on top of a scope it's more like 3" now cant the rifle and you'll be shooting the door frame or other cover; maybe even the good guy or family member you want to save.
On the other end of the spectrum most shooters can't hit a IDPA target at 600 yards with iron sights and a large percent can't do it with their scope. Add in factors like wind, humidity, alltitude, temp changes and standard scopes then a shooter that does well at 100 is lost at 600. I see it in every class.