I think disguising with it should be re-allowed, for several reasons:
> Pulling off the disguise in the first place requires you to get a backstab without any of the other guards noticing, and considering you'll still have the red "rebeller" effect for a short time, that makes it even harder.
> Let's face it, lots of Jailbreak Spies aren't exactly the sharpest tools in the shed. Finding a Spy who convincingly acts like a BLU and doesn't just run right at other BLUs or do something stupid that gives away their disguise is fairly rare.
> Not only does it require the Spy to not get noticed, but it also requires that no BLUs take note of the BLU count on top of the screen or on the Scoreboard, no BLUs Spycheck, no REDs snitch, and no one ghosts.
With all of that in mind, it isn't nearly as OP as people say it is, and I feel that E.R., as well as it's ability, should be re-enabled.
+1