Well.. you know you could achieve the same effect with no variables and no Parallel Processes (other than the conversation event, although it's most likely on Autorun).
You just need to create a new, blank page for every character and select a Condition switch. Now in the Autorun/PP event that's processing the cutscene/conversation, at the very end turn on that switch rather than doing the Control Variables. Remember to also create a new page with a condition in the conversation event to prevent that from repeating too.