I can’t comment to the warping issue, I have a mous case still for the 15pm and it looks fine but I also did not use it for long.
My thoughts on the newest Mous version for the 17 are the same as the older version, it just didn’t feel like an $80 case. Fit on mine wasn’t perfect, the fabric back is alright but the cutout for each inlay just looks odd after a while. I could see the fabric getting soiled or frayed after time. For me there are too many other good cases to try, but could understand sticking with the Mous if you liked the branding or something about the particular design. If the back of the marine was the same material as the sides/frame without the fabric, I probably would have kept it.