Just spoke with US again, still no fix and no idea when it will be back up and running. Might try asking UA; getting fairly direct *A awards out of PER to North America can be difficult so really don't want to lose my existing flights (PER-SIN-HKG-YVR, HKG-SIN-PER).
If you hear any news, would be grateful for an update.
Cheers,
Michael
I'm happy to report I was just able to successfully book UA flights using US miles. (not ticketed yet, but booked, and have a UA PNR).