I didn’t want to rewrite most of your code but am not that comfortable with Split Tree (which I left in place for the ‘Filtered Points’ group) but felt that it would be easier to scrap the ‘Filtered Normals’ group, combine the two sets of points and get surface normals all over again (white group).
Perforate_Cylinder_2021_Jul9a.gh (28.9 KB)
SDiff was way too slow for me so I borrowed a recent Python contribution from @kev.r which is MUCH FASTER, though still takes 40 secs. for this (so is disabled in the GH file).
