it's generally a good idea to have at least some initial starting cap because people get really pissy if you introduce one without warning, but it is your game at the end of the day so you can do what you want. i know some mods wait to see what the opening tdm is like to make a decision. if your tdm is flooded by one cast you might want to decide to put a cap on it for instance just in case. but if it's small and slow you might not need to bother.