Iím also a fan.
It looks like the PVC you are using is 2Ē schedule 40 Ė I know that to be rather stout stuff, and hopefully all you need.
Like Randy says, I donít think youíll get much from adding foam (been there, done that). You could add an idler wheel at the midpoint above the top roller and below the bottom roller. That will cut your bending in half. Alternatively, you could go to a larger diameter on the PVC, but I think you are on the right path. Gin something up quickly and try it. Anticipated problems are often replaced by something you never though of.
Pls keep us posted on the progress.