Hi Alan,
I have the lean limited to 15 degrees right now. I am using counter-phased cams to couple the swing arms weight-shift induced motion from one side to the other, with the cam shape determining the amount of righting force at a given lean angle. If you think of the cams as variable length levers, moving in opposite directions, you'll get the idea. I'll try to remember to get some video for you.
I'm playing around with cam profiles and phasing, and I have found some that are just plain scary to ride, and others that hardly move at all, so I clearly have a lot of work to do to find the sweet spot. But, hey, it keeps me from annoying people on the board:)
No worries about the swing arm hitting the ground, the trike will be laying on its side by then.
TTFN
Dennis