Yes I came across that view of an unbombed beach as well as a
single description of a shell hole. What I have not found is what and who was supposed to try to shell the beach obstacles. Logically the biggest shells could create such damage as to give problems for the landed vehicles. I suspect the Allies might have been depending on smaller artillery and bombs. In which case it might have been left to the DD tanks and howitzers in some of the landing craft. But they were late and could not see their targets while at sea. So it fell to the engineers. BTW it Also seems I was wrong about trip wires, they were used, making antitank mines trip on more than just vehicles.
Love the bangalore idea.