It is a big proportion of travellers on the triangle.
Maybe it's time to limit PB to those travelling in J or higher, together with QFF WP and above (plus OW equivalent)... though I think that's not in line with the OW benefits. They could call them in sequential groups I suppose, with SG/OWS boarding second and together with Y+ on INT flights. So long as OWS are called ahead of general boarding, then they would comply with the OW PB rule.
Cheers,
Matt.
p.s. I reserve the right to change my tune after I can no longer maintain WP