Hmmm, I believe GEP WILL remove fillers.....but I don't think that should be the determining factor as to whether or not you should use it.
I wouldn't worry too much about what products will remove what fillers, because until the paint surface looks perfect, there are benefits to additional applications of any paint prep product, despite the way they "remove themselves".
With that said, in my opinion, #9 is perfectly sufficient as the final prep product prior to applying wax/sealant. I would just use either #9 or GEP (doesn't matter which) and when you are happy with the way your paint looks apply your final wax/sealant.