If folks are sitting in tower AFK hoping for war win perks, they are Bish or Rook, and the high eny effects only Bish or Rook. I can't see why we would want to change this
Seriously though, getting booted after a couple hours of inactivity probably wouldn't have poor unintended consequences. If one minute before you get the boot you get a pop up telling you its coming unless you do something, it would be hard to see any issue.
On another note, I would strongly suggest that anyone who's gameplay is "ruined" by high eny give some of the other rides a chance. Other than running away, there are plenty of rides that are always available and very capable of accomplishing stuff.