Rites of the High Exarch usless?

I just wasted 10 ICC commendations on Rites of the High Exarch for my froob NT hoping to make IS a little more viable for my squishy NT, but only hides you from aggro if you don't attack anything. As soon as you attack a single mob, all other mobs within aggro range attack you. What's the point of this item since you can't get to the second floor or the new Re-Incarnator area without killing a mob and you are open to aggro if a teammate attacks something?

It's not like the Initiate Teachings of the Immortal One which at least lets you run around ToTW without drawing cultist aggro (though I've noticed that bosses still aggro if you stand around them for more than a moment -- at least Defender of the Three did). In IS, it's basically only useful from walking around the first room. Also, in ToTW, it seems that if a cultist is grey to you, then they don't aggro you if you attack another nearby cultist while wearing the Initiate Teachings of the Immortal One. Is it the same in IS too with the Rites of the High Exarch? because most of the mobs in the first room are at least green to level 200 characters.