Just to make sure: this thread was not intended to prove any inadequacy on the part of SRAM or the PC-1. I'm fairly sure that I am the inadequate one here, because of making two mistakes:

1. I left the chain a couple of links too long;
2. I didn't push the pin back in far enough when reconnecting.

The first made the chain jam up when back-pedaling in the small-small combination on the work stand. The second enabled the side plate to come loose and get caught by the dérailleur cage.

The way it has held up during the past two weeks makes me think I've at least resolved these two issues.

Eroica Limburg next week and La Savoureuse in August. I'll keep you posted wrt chain behaviour.