Hi Tim,
Thanks for purchasing Pro and WooCommerce Tickets.
You are correct they are separate systems for the most part.
WooCommerce Tickets is a simple ticketing system that creates a Ticket Product in WooCommerce and uses WooCommerce for the checkout process. We do not modify that process, which is one reason we did not include a way to use the Additional Fields in Pro.
If you are looking to add additional Fields in the checkout Process that would be handles by WooCommerce itself and this is a free plugin that can help add fields there:
Checkout Field Manager (Checkout Manager) for WooCommerce
Is that what you are looking to do?
Thanks