inability to emergency stop, excessive ability to spear your leg in the event of a crash.
they won't let you ride without bar-ends, how could they allow this.
also, all the other kids would point and laugh and it's just not worth it.
a better way to accomplish the same thing (and you still should not do this) would be to get some single-pivot brake-only levers and mount them right near the stem faceplate, then put the IAB arms on top of them, effectively removing them from the aero profile. they won't spear you, you could emergency stop if you had to, and it would be so, so much less offensive.