It's been a long 3 years since I've submitted a BRG and things may have changed a little. At the very least my previous trusty OTAs no longer exist!

The hotel I'm trying to BRG only has prepaid refundable or fully flex rates available. The OTA has prepaid non-refundable. Is it still possible to book the prepaid refundable rate and BRG with the prepaid non-refundable? There's no way for me to book a non-refundable rate on Marriott! My claim was rejected because the conditions were different...