Having an afk timer does not work... there are many ways around them. Not to mention, I can hear the whines now, "I logged in to pink so I can fly with my squad and I got logged off. This isn't unlimited play for $15, I want my money back."
If anything, they should expand eny to account for zones. This way, even if your side has a lot of numbers, you can fly against a larger force in the area and not suffer from ENY at all.
For example, you log on and there is an ENY penalty of 10 for your side. So, you find the biggest pile of red you can find with the smallest green and your ENY penalty is gone. In fact, ENY may even affect the other side if their numbers are high enough for the zone, regardless of the numbers of players they do not have.