I’d recommend changing the parental controls so that a player cannot start a NEW match on Heroes of the Storm or other match based game (OW, etc). Right now, if a Player is in a match, parental controls will just disconnect him or her from the match and that’s really bad for ranked games, leads to toxicity, and is unfun for the other players in the match.
There should be a way that parental controls can allow finishing a match, but not starting a new one if it’s after the cutoff time.