Hesitation after burnout.

would you hear it if there was a popped power valve? Can vaccum secondaries have anything to say?
You probably won't be able to hear it, but it will run rich & have a stumble. You can change the spring in the vacuum secondary pod to a lighter spring to see if that any affect. Just make one change at a time until you resolve the problem. Multiple changes will have you scratching your head, wondering which one fixed the problem, or made it worse.