I've used 24" rolls of Ilford GFS in my Epson 7900 and it has quite a curl, especially toward the end of the roll. I have used a de-roller on it but with less than satisfactory results. It does take out the curl bit leaves a permanent "wave" in the paper where the leading edge of the paper wraps around. This does not happen in cotton papers, and I haven't had the issue with Epson Luster. I've been told that due to the small diameter of the de-roller and the extra pressure where the leading edge of the paper wraps around, these stiff alpha-cellulose papers are slightly "crushed" there. You'd be better off with a larger diameter home-made de-roller or flattening the prints over time between weighted sheets of foam core or similar.