——Close Air Support from 30,000 feet is possible these days.-——
Maybe, but if I have a heavy MG position 75 feet from me, I prefer CAS that can get an eyes on after I pop smoke and myself not get hit by the resulting shytstorm.
If that MG position is truly 75 FEET from your position, I think I would trust a dedicated weapons system operator looking at a magnified video or IR view of the target and lasing the exact spot until a 500 lb bomb turns it into a smoking hole, than I would a pilot with Mark I eyeballs trying to unload 30mm rounds while also avoiding controlled flight into terrain.
Or more realistically, you call in an Army AH-64 Apache who will expend a laser guided Hellfire.