Hi ComplexDarkness and trav,
Sorry for delay... :(
The miniskirt was tested in P4, PP, P5, P6 and P7 and the automatic JCM works.
You need to load V3 as a first figure in the scene then:

• turn off IK  of your V3 character
• apply the pose that you want to V3
• select a V3 actor (i.e. hip)
• load the miniskirt and conform it to V3

The miniskirt automatic JCM's (to apply the right rotation like twist, bend and side) need to read the character (V3).

Hope help you and have a nice day, Mav :)

P.S. Sorry for my poor english