The 7mm Remington Magnum with a 150 grain Nosler Ballistic Tip at a MV of 3100fps has anchored the most whitetail when the CNS was not impacted. It is more common for that combo to put whitetail down at impact on rib hits than any other IME.
My go to rifle used to be a 7mm rem mag using 140 ballistic tips at 3200 fps. My experience mirrors yours, hundreds of lung shots that resulted in instant drops. I hardly ever recovered a bullet because they grenaded, but they hardly ever moved out of their tracks and there was massive internal damage. A couple of blow ups had me switch to tougher bullets.
Getting a DRT from a lung shot is different than the high shoulder shot. They drop from trauma to the spine with the high shoulder shot. A tough bullet won't give you a DRT from a lung shot, they'll go a long ways hit by a tough bullet through the lungs.
