Hello Cat-thulhu,
No, it will not hold up the order. When you submit an order with a shipping method of 'Ship with subscriptions' the item goes into your sidecart. When we generate a subscription order it looks in the sidecart and pulls out any items that are ready to go. But it won't look at the sidecart again until the next subscription order is generated. So if you add an item to your sidecart after a subscription order is generated it will not go into the subscription order, even if it hasn't shipped out yet. When we run the November authorization it will look in your sidecart to grab any items that are ready to go, but it will ignore ones that aren't. So putting the dice in your sidecart won't hold up any orders.