Barn- I'm gonna try your method of the clock and route sheet (i.e. no odo).
You will ALWAYS have discrepancies in odo mileage from the course mileage, but the time will always be right (assuming you have a good clock synchronized with key time). If you hit a marker early, slow down. Hit it late, speed up.
Generally, I haven't really worried about keeping time. I'm a C-rider, but I've gotten a lot faster in the last year since I got a lighter bike.
"This place fucking runs on beer, you buy the right person a beer, and you get a job, a blow, a place to sleep, whatever.
You're hot, cold, thirsty, hungry... beer will fix that.
Beer is a god damn miracle, and don't you forget it!"