Hi Mark,
Knowing my leg condition when we arrived at the Norwich YS, I did moor next to one of the ladders, as the tide was so low, my crew could not get off the boat.
However, we were asked politely by the BA lad on duty, to move the boat away from said ladder, as they are for emergencies only. He kindly helped me get the boat as close as was safe to the lower concrete quay so "Scoot" could get off easier.
So in a long winded reply, yes do not moor in front of said ladders, is the answer, well so the BA said.
Iain.