Any question answered...

No, for two reasons.
1: I wouldn't use a Fixxer for skidding, pretty sure the splines would be fucked pretty quickly
2: Very few Hed hubs have the necessary spline-drive freehub, just a few H3s from the early days AFAIK.

I won't really be skidding on it at all, track use only, I was being facetious calling it that, but I can see it's quite misleading.

This looks better in that case, but will this work with Discs as well as H3s, do you know?