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.
Day gives way to night on the store front mannequins. The audience with Mona Lisa grins.
Moonlight builds emotion as the players scuttle in. Pull the curtain back and let the show begin.
Lunar mischief under low light discipline. Here the tiny monsters hunt the harlequins.