I only see an issue with multiplayer lock-stealing games if the process to re-lock balls is especially difficult. Games like Radical! or Fire! both force you to slog through the lock lighting process again to re-lock balls, which is a real drag. Games like TNA or Taxi aren’t a big deal because you can just pop them back in without difficult requalifying.
So I think it’s fine for the TD to make this decision on a game by game basis without creating a blanket rule across the board.