Hi @Brad_Kubie,
The Carrier Service Request sent is meant specifically to send the needed information for shipping services to calculate and provide estimated shipping rates during checkout. It isn’t meant to send all information on a checkout or cart, just the information needed to calculate shipping.
If your app needs to know the discounts applied during checkout as well, I may suggest subscribing to the checkouts/update webhook to get notified when a checkout is updated with information including applied discounts.