Keith, I did pull up gently on the plyban while filling the curds, and each time I flipped and redressed it (six times). I think the wrinkles came from the initial molding (pressing under whey) before first flip. I noticed them on the first flip, and they never seemed to change, although it is hard to tell. One wrinkle looks very much like any other.
What I do is firmly and evenly press the curds into the form with my hand as I'm filling it to try to get even density throughout. Then I pull up on the edges all around to eliminate bunched up material.
The plyban is much thicker than regular cheesecloth. Maybe I need to pull up more aggressively while holding the curds down with my hand?