Hung start procedure
Hi Anchor river,
Hetfield has already stated that the reason for using the CONT RELIGHT position is the energize both igniters in case the hung start is due to weak igniters.
Now for the HP VALVE closure I would say the reason might be an air bleed leak through the associated HP VALVE that might have caused the HUNG START and we want to isolate the pneumatic lines to prevent this.
Then again, this is only a pilots point of view so I stand to be corrected.
Happy landings
ROTS