If you want both a stopped and a running contact how do you train it? I have trained a stopped contact before and I have a dog who is small and training a running contact was not an issue because she doesn't jump over the yellow. But what if you want the choice to use both with the same dog? Also, what if I want a running A-frame but always a stopped dog-walk? Any special issues I'd run into there?
How about 'just teach her a "wait"' to be taught and used in any kind of situation as a stopp signal (you will need to train another signal for running on) and if ready, when she is doing fine already with it without leash from any kind of speed and emotional state, transfer it to the obstacles?
As a stop you might want to ask for in competition is probably very short, you might need to train these two signal over obstacles together with very varied duration in between, so that she will not anticipate the 'run again' signal during competition and run on, before you want it.