Flew Air NZ's Biz Premier in November. At the gate it was apparent on both the outbound and return that they could have benefitted from more PE seating.
There is however the issue of manpower deployment. I observed that the crew looking after BP on the 777 also looked after the PE cabin. There didn't appear to be a dedicated crew for the PE service. Adding more PE seats would diminish the availability and personalized service in BP unless they were to add additional and dedicated crew members.