If a prop is parented to the head (it doesn't have to be hair) you can change the extension and put it in the hair folder. Anyway, prop or conforming figure? I don't know about the other guys making hair, but to me the choice is real simple- if it gets close enogh to the shoulders to touch when the figure is posed normally it should be a true conforming figure. I mean "true", unlike the stock P4 conforming hair which is more-or-less a prop that has joints, not really conforming. My hair works just like clothing, move the shoulder forward and the hair adjusts. It isn't perfect, but it works for 90% of the poses without modification. My Las Vegas hair works like that, as will the San Fran hair when the update comes out this week (the existing one has a chest part, I added the collars, too), I'm going to have a update for the Hollywood hair that has a conforming model too, for the longer version. The bobbed hair doesn't need it.