Customize Magento Checkout Extension

I have a premium extension called Cart Reservation for Magento ([login to view URL]). You can view the documentation and demo. HOW IT WORKS: The extension reserves products in your cart for a certain amount of time. When time runs out it empties your cart. Also, when you proceed to checkout it resets the timer so customers have more time to checkout. CUSTOMIZATION NEEDED I want to use this extension with another checkout page instead of Magento's default checkout page. The new checkout page is called IWD Onepage Checkout ([login to view URL]). I want the timer to reset when you reach IWD Onepage Checkout.