For several of my type projects, I’ve received requests to add some of the more obscure space-like characters. It would be great if these could be auto-generated from a list in the «Separators» category.
Most of these characters are empty and have well-defined advance widths, so they should be easy to auto-generate. For the less strictly defined ones (like HAIR SPACE), you could at least choose a sensible value as a starting point. It would be much preferable to having to dig up the unicodes and definitions each time I make a new typeface.