hi Jamie, you have to rebuild the wrapped surface. first explode it delete all surface besides the inner one which touches the cylinder and rebuild it to a higher amount of points, i used degree 3 in both directions and something like (U) 100 by (V) 300 points, then unroll this surface and extrude those cirlces (better this way otherwise you have to loft the flowed circles with offsetnormal wich is more work) it then applies them properly.
there is still some natural stretching along the folds of course but they do not overstretch anymore. then you offset the surface again outwards to the same thickness and use booelean difference.
ps: i actually just offset the surface randomly. you may have to repeat it if yo need the same thickness. boolean difference took me a few minutes so you might have to be patient depending on the age of your machine.
1.3dm.zip (15.6 MB)