Lowering a pop-up TC....is there some trick to this?

My old camper had the same issue. I solved it by lowering the top part way, then pulling the mattress forward so that the handle was blocked from rotating by the steady pressure of the mattress. Ran around and tucked, being careful not to put my fingers in the way. I used a piece of dowel with a rounded end. Back inside and it's, hold the handle, push the mattress back, and slowly lower the rest of the way.
My new camper has the fan and that works beautifully.