Just a quick comment on the AE suspension.
It does have progressive caster which changes RC and all the other geometries - it does so on purpose.
You can get arms (or used to be able to) which don't (or had much less of an impact) and they didn't work as well.
Now - realize that we weren't doing the extreme amount of engineering that Jon is doing, but then a lot of what he's doing has been tossed (the lube on the kingpin, which we had tried, the sway bar, etc) and now he's basically using a longer kingpin (which many of us had done) and springs to adjust) along with a sweet (and really sweet) shock setup basically to dampen the action only.
These cars steer so aggressively that you actually want some degree of caster change - it's beneficial at the extremes when it comes into play. We've played with some of the geometries and each time we do, we keep going back to where we started. We looked at the Switchblade front susp (endlessly adjustable) and went back to the original.
There is so little space under the front of a GTP style body (which is so much superior to any other style) that it makes any complex suspension very very difficult to deal with. Frankly, I'm really surprised that Jon was able to get shocks under there (okay - seeing Jon's work, I'm NOT surprised. . .
And I'll wager that adding a more complex suspension isn't going to reap the rewards you're looking for.
Just look at Jon's runs. He's back at the (basically) stock front end (modified kingpin length and springs to adjust) with shocks to dampen.
Shows the strength of AE's original engineering to cram that performance in such a small package. . .
Anyway. . .carry on with the engineering!
I'll dip into Milliken this week to see if I can get any insights.