I think perking planes is a bad idea. ENY limiting, as much as I dislike it, is better IMO. Perking a plane, people suddenly fly to live much much more than if it's unperked. I think most would agree, we already have plenty of people who one pass haul backside without adding more planes to that list.
My personal theory is there are a few planes, like the Yak and maybe 109K, that have much higher ENY than they likely deserve to give people something to fly when ENY is higher.
Wiley.