Short answer: No.
Each pre-order must be purchased on its own transaction. That way your credit card is charged on release day.
What happens if you put a preorder book in a cart with other items? Your cart will empty on you (sorry!).
For preorders, on book release day, you will receive a link to get your book via email from [email protected]. Make sure to whitelist the email address!
New to Bookfunnel? Worry not. Help is available at every step. Bookfunnel offers excellent customer service. They can walk you through any quirks unique to your device or software.