[Perfectlap]

the pinching has mostly to do with air temp.
I never do the chop, if you give the top a chance over time it
remembers where to bend. I have no crease whatsoever.

BUT as the fall temps come in the plastic becomes more rigid
and the top's "memory" get mudled and you get that pinching.
The chop is pretty much mandatory at this point. Its not really
a chop but lowering partly and prodding it to make sure the bend
is even and uniterupted. Another thing to do which isn't just for preserving the glass but the canvas as well is to blast the heat with the top up before lowering it. I think lowering cold canvas/plastic adds to the stretching and wear as it pushes over the bows. Cold friction like in an engine.... not so good.

p.s.
+1 on frequent REnovo use for removing swirls. It will leave the plastic
crysal clear. Maintain with Plexus and don't spray directly onto the window, you'll get overspray onto the top. Renovo is the one advantage plastic has
over glass. Very hard to remove scratches froms glass!