The spawn issue is a known issue and is being worked on.
As far as specific airport updates most of it relies on if the changes are visible to the available scenery. The satellites do not refresh their content that frequently so sometimes it takes a bit for the imagery to catch up.
You are welcome to read up and join the airport editing team. All you need is a computer, attention to detail, and willingness to learn and listen to feedback. Check out Infinite Flight Airport Editing