For version 9.8 we have a simple feature that will allow the user to add a REMINDER product (or products) at the shopping cart page, the payment method page and the checkout confirmation page.
The administrator can choose which pages they would like to show the reminder and there will be a place to input Product ID's. There is also a place to edit the REMINDER text for the customer to read.
For example....perhaps you have an Event Programme you want to sell or some refreshments for the interval?
It's a simple nudge for the customers at checkout.