My first post! I've lurked here periodically and this has been a great resource, so thought I would share my successful reimbursement for a TICKET!
Data point:
Booked RT ticket with PRG on 10/8/18. Technically this was two separate transactions - outbound ticket was purchased in cash ($90.20), inbound ticket was a miles redemption (11.5k, $5.60 in taxes). Was reimbursed separately for both charges on 10/11/18.
I had not used any of my airline credit prior to this transaction, and only set B6 as preferred airline a few minutes prior to purchase.