Final update; now confirmed on SQ
To the professional and helpful PC agents, Jairo and Jennifer ^ for working with me on this reissue.
I now have my SQ BP in possession. The agents had to walk to SQ to complete the reissue, arranging coverage here at PC. Then, I had to walk to SQ to check in with the SQ record locator. With just a slight hiccup at the SQ desk while they found the SQ locator, it worked. I heard that the reissue RQ went three levels up from the SQ desk here before it was approved.
So, an unscheduled visit to DME on the way but I arrive in SIN ahead of my original sched. This preserves my trip quite well, I only lose a breakfast appt in GUM on the outbound. My bags will follow me to SIN, after visiting GUM. I hope my suit makes it on the original flight, I need it for my appt the following day.
Without PC membership I'd be sunk. I can't imagine the CS desks in the E terminal going to these lengths to make it work.