My point about the chainstays was more related to the extending chainstay length (and wheelbase) due to the high pivot. A lot of people have said, and I agree, that high pivot bikes are harder to corner because they extend through the travel. So when the chainstay length is already long to start with and still extends I through it's travel I can't imagine it cornering well. Perhaps this is related to the wheelbase as dilzy said. To be honest I'd never really considered that point.
I am currently designing a 4.5" high pivot bike that I hope to build around xmas and I'm designing the bike around the sag point. I figure that way the chainstay length comes out at the length that I want when I'm on the bike. I might post up some design pics of it soon for the intense scrutiny of the Farkin crew
The first high pivot dually Benj (on here) and I worked on seemed to turn out pretty well using this method.
Come to think of it, the BB height and HA on the Scarab kind of remind me of the GT IT1 which would have been an awesome bike if they had just tweaked a few angles in the design.