Everyone loves the jets. But when entering a game world and I want to run a niche airline, there’s plentiful 737s available but nothing small available. This is exacerbated by the production line of certain aircraft being open for a year, receiving no orders, and then closing.
An example of this is a Cessna Caravan. If I enter a game world and there’s no used frames on the market, and production ended at a year because of no orders, I can give up the dream of hubbing Bora Bora.
My suggestion would be to keep aircraft in production at minimum for the length of time they did in the real world. After that date, market forces can decide whether the production line stays open or closes. I realize there would be a data gathering exercise to determine production end dates.