I talked with knowledgeable people and there is no easy solution to this other then measure each file duration and put a wait block. One got to be careful about this. Even the following did not work. It should go to to the Do only after play is done, but as I said there is a bug.
@ioannis I will file a bug report after a day or two if I dont hear from anyone and then close this. Thanks to all who looked it.