BA used to fly a 747 into PER ex LHR albeit via SIN..now i wonder what the stats were on that in terms of through loads etc
I operated a fair few of those and whilst I can't comment on the yield ('cos I don't know) I do recall those flights generally being "quiet".
FWIW When we had the traffic rights for the PER/AKL extension it always seemed to me that the load picked up again due to joiners at PER.