Complicated conveyor setup

Hello! I have a customer request with a complicated conveyor setup.

This is a roller type conveyor where product travels in palettes, and at each station the rollers can be rotated/lowered so as the conveyor moves other palettes, some stays in place. I beleive I can set this up with decision zones, but I am unfamiliar with this function.

The other complication is that it is a  two layer conveyor, so the other side is used to transfer the palettes (still with product) to the opposite direction, like a loop. Palettes are being lowered at the end and placed on the lower side.

How can I set up this conveyor?