I got 1 sheet of Yupo to try it for Pt/Pd printing. I was able to coat it even it did absorb only about half the volume most papers would absorb. But almost no image was formed.
There was a very faint image printing out and most of it disappeared during development. I found it interesting as Yupo is made from polypropylene and lacks any polar groups (in contrast to cellulose). So paper (and sizing?) is not an inert substrate but part of the chemistry of image formation.