[jakeru]

Sounds like you could use the M030 suspension option. The added roll stiffness it provides over stock "soft" springs will mean reduced body roll, and therefore less dynamic camber change. If you care about racing class legality, M030 would likely be stock-class legal, too.

While you're at it, make sure your bump stops are like-new condition. They are not something that rarely works - they work constantly in parallel with the springs and are essential (with the stock spring configuration) to controlling suspension compression.

About the idea of changing alignment before/after each event, I remember a guy I used to autocross would change his toe at the event site, both before and after each event. He also would swapping on/off a set of racing wheels/tires, which was very common for many racing classes, but changing alignment as part of the weekend routine - not so common. This is on a front wheel drive car where front toe may be important enough to justify this, but it had the same suspension style (macpherson strut) as our Boxster's. He had a home-made trammel bar dedicated for this purpose that he'd set up laterally across the wheels, and would quickly make the adjustments on one side at a tie rod end.

Adjusting camber before and after each event, however, seems pretty crazy to me. The reason is because, adjusting camber, even a small amount, will dramatically throw off your toe setting. Toe setting will need to be very accurately adjusted after each camber adjustment. So you're basically looking at pretty much a "full alignment" there.