good stuff! i have that same rear monocaliper
just a suggestion, probably more work than it would be worth but if you want to mount the rearset closer to the frame, you might be able to modify the rear brake lever to fold outward so when you kick start it, you can fold the brake lever out of the way then start it. then when you're done fold the brake lever back. i would think if its hinged to fold outward only it wouldn't mess with the up/down motion of the using it as a brake since you're pushing straight down opposed to out... although if you did this i'm sure you would want a spring to hold it in, and some kind of lock to hold it out when you're kicking. although it might screw with using it with a front wheel in the air! xD
keep it up, duckman.