$params passed to payment gateways don't include line item prices or additional participant line items

Despite the confirmation page having all the required information about all participants and the line items (read price sets), the $params array passed to the dotransfercheckout functions does not include all of this information.

If your payment gateway implementation requires sending over purchases as separate line items (for tracking/tax/refunding individual items/other purpose) this information is only partly available.

Missing info:
Line item prices for primary participant
Additional participant line items and prices