Question for everyone: is it possible to make a monthly order after you already combined two orders? I have Chiaki and Sepang Miku supposedly releasing this month, both are combined into one order. I don't think it's a monthly order though, just a regular ship-when-they-arrive order.
I'm not sure what you mean, but if you have two items releasing this month in the same order and go to make another order for an already available item, preowned item, or item also shipping this month, you should be able to get it added to the original order.