I think you misunderstood me. The machine used has nothing to do with it. What I'm referring to is that there are two cam bolts to adjust camber and toe on each rear wheel. On the Boxster, neither one of these bolts adjusts camber or toe independently. Adjust either bolt, and both camber and toe change. This can make alignments slightly finicky.
Typically a buddy and I have used strings (or something similar) to align cars with upper and lower A-arms since the camber and toe adjustments were pretty much independent. Not the case on the back of a Boxster.
I, too, plan on dialing in different toe settings for autocross. The "toe" link will adjust mostly toe, but you'll also change camber.
i did misunderstand you. you are absolutely correct that adjusting camber at one wheel will affect toe at that wheel. adding neg camber will toe the wheel out.
Fab, not sure of your exact location, but if you're North or West of Boston, you might want to check out Auto Sport Engineering in Stow or Autobahn Performance in Peabody. I've used Auto Sport myself and really like them; I have only heard good things about Autobahn as well (from former forum members).