The main reason all this tends to get pushed down to the FS layer is because of the question "what happens if the user accidentally creates two files with the '

The main reason all this tends to get pushed down to the FS layer is because of the question "what happens if the user accidentally creates two files with the 'same name' but different coding sequences". When it's the difference between README and readme I'm inclined to be like "well, that was dumb, move on with life" but it's different somehow for visually indistinguishable situations.