The mystery of the orange flavour of the Pyrat Rum has not been solved yet. Bulk rum from at least one other Caribbean Nation is blended with the Demerara Rum before bottling. That other bulk rum could be the source of the unique flavour.
I'll have some more to say about this when I finally review some Pyrat Rum as part of the puzzle may be related to what DDL calls their "High Ester Still". (I took a nice picture of it in the Old Plant.) Some of the Pyrat Rum is distilled upon this unique still and I was told that the still is capable of producing a very unique high flavour rum.