Stopping on the whistle

Ram Jet Rocket Dog doesn't ever slip a whistle. She'll stop, but honestly, she takes her time and several steps first. This may be because she's running really fast, so to some extent, it's physics.
Because of the speed thing, I believe that I may always run blinds with lots of whistles (which aren't penalized in Hunt Tests... as long as the dog is making progress toward the blind with each cast.)

BUT... having said that, I believe I can improve her stopping on the whistle. I've begun using highly desirable rewards... either a tennis ball, or bumper or (today) a duck. I send her for a "blind" (orange bumper) blow the whistle, and then toss the object. (She has to remain seated while the toss is happening and only go on her name.) Today I had the duck with me. Her whistle stops were way better. I mixed it up. Sometimes, I just gave her a cast to the blind. Sometimes the duck. If she was running a true line to the bumper, I just let her go.

She has responded to positive training methods and I think her heeling and autosit are pretty well conditioned. It's neat. So we'll use a similar approach and see if we can condition a good whistle stop in much the same way.