Think this is something that's only going to be used in the API. If you are planning multiple waves it may be helpful to add the next waves to the GM layer and then add their turns to the turn tracker. Those turns won't be visible to the players. When you're ready for the next wave, use Ctrl+K, select your next wave tokens, press Ctrl+Shift+O, and all your tokens will become visible and have their turns added automatically to the tracker for the players. The only disadvantage is you'll have to click through the extra waves during the previous ones. Just as an idea to help make it go faster in game.