I think the issue is that native OS things like the windows command line, say, don’t always do this. Check the results of their ‘cd’ commands with Japanese Yen

I think the issue is that native OS things like the windows command line, say, don’t always do this. Check the results of their ‘cd’ commands with Japanese Yen characters introduced. You can see that the path descriptor somehow has updated to a directory name with Yen (or a wide backslash) in it, while the file system underneath has munged, and put them into an actual directory. It’s precisely the problem that you can’t control the rest of the API surface to use W that is the source of the difficulties.