Itachi intended on using it on EMS Sasuke originally, so it likely would've worked had it activated on him.
It didn't work since Sasuke and Itachi shared the same eyes. However, it worked on Itachi since he's not immune to genjutsu.
Don't think it works like that. Itach is Itachi, sasuke is sasuke, casting a jutsu on one brain doesn't make it effect someone else regardless of eyes
KA casts on the eyes, not the brain. Itachi said it would activate on his eyes.
You must be registered for see images
it did work. how you think sasuke lost in Vote 2?
KA was programmed for him to protect the village. If he would've won he would've destroyed the village