SUMMARY: What I learned today about keeping up with Boost.
A friend watched me do some long runs trying to get Boost to run ahead of me over a fairly straight line of jumps instead of waiting, turning back, or spinning. She told me that I keep slowing down when Boost gets ahead of me. Of course I don't mean to; what I *do* do is point with my arm to try to keep the pressure on and yell "go! go! Hup!"
This was a "Doh!" moment. Apparently I cannot run as fast with my arm pointing ahead of me, while yelling, as I can when I just pump my arms, shut up, and run like hell bent for leather (whatever that means). When I did that, Boost didn't get quite as far ahead of me, but furthermore, the important thing was that she kept going straight, over jumps. Not super-driven going confidently away from me, but not stopping or doing refusals, either.
OK. We're going to try that this weekend if the opportunity arises.