what corps are based out of perimeter?
The fact that Perimeter has a docking tether would fix some of the station games - although I am sure there are creative exploits yet to be discovered!
The fact that Jita has 30 second invulnerability timer fix some of the station games. Issue is that most of players don’t know about it or don’t use it.
You can be bumped outside tether same way as from aligning to safe spot. Only option is instant undock bookmark since single bumper will make you unable to anything expect redocking (if he won’t bump you from dock range).
Is Jita’s invulnerability timer different from the timer on all the other NPC stations?
No, but Tranquility Trading Tower is not an NPC station.
I have an excellent insta undock at Jita 4-4. One that isn’t even remotely endangered by any grid extension.