What request/response trigger shows available tender type options for returns

[RethaLam]

In POS, if one has an on account customer and one does a pickup for an order, when it takes the user to the cart and the user concludes the transaction, one of the options to pay with is On-account.
The pickup also invoices the order in HQ.
When this order is returned, the on-account option is shown as a valid option to use to return the order. This is great, we requested MSFT for a long time to recognize on-account payments in POS as a valid payment method to return against because it is valid in HQ. So we are very happy that it is now available.
However, if the user takes a POS order and pay on account in HQ and invoice the order in HQ and want to return the order in POS, then there is no on-account option available to this order to use for the return.
So, even though MSFT now accept on-account payment as a valid return option if the on-account payment option was selected in POS to pay for the order originally, it still doesn't recognize the on-account payment if it is done in HQ.
Looking on the channel DB, I see there is a view called: [crt].[RETAILTRANSACTIONPAYMENTTRANSVIEW].
This view listed my on-account payment done in the cart.
So my guess is that MSFt only looks at the RETAILTRANSACTIONPAYMENTTRANS on the channel DB to see what payment was used for the order instead of all payments for the specific order.
Our retail return policy is set up correctly to allow on-account payment to be returned using on-account payment. This is not the issue.

I will have to add an extension to do a realtime call back to HQ to pull the on-account payment tender type from the order in HQ.

So can anybody please let me know what request/response trigger on the CRT I can use to accomplish the above.
We need to be able to have the on-account payment return option available for the order regardless if it was added to the order in POS or HQ. We have the omni-channel feature turned on. So HQ orders can be completed in POS and POS orders can be completed in HQ.
Thanks in advance.