My experience with 3880, p800 and p600 is that using the front feed option eliminates the pizza wheels.? It is likely that the p900 will do the same. There is no hidden instruction, it assumes that you are loading posterboard. I use a carrier for DTP polymer gravure? (window cut into 2 ply matte board) so that is my default anyway - for film you may want to try attaching it to a carrier as well -because I am pretty sure that the? platen gap automatically adjusts for thick media.

Berel Lutsky