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Actually, the answer is, as I said, rather pedestrian.  The Customer was rather concerned that our analysts hadn't gotten things quite right concerning inlet airflow and that the higher AoA's would see stalled inlets and dead engines, normally meaning a lost aircraft given the nature of the controls.  Those pipes are exhaust pipes for two hydrazine-driven emergency power units (straight out of USAF stock) installed in place of the RH APU.  They were only supposed to be extended as they pushed to higher AoAs but were out on the first flight "just in case".  To the best of my knowledge, they were never needed and the analysis and predictions of inlet flow were either accurate or conservative.  Hydrazine tankage was placed on a pallet in an empty bay on the RH side of the aircraft while the equivalent bay on the LH side of the aircraft contained a pallet with several large batteries to ensure there was adequate electrical power throughout the restart effort.