Who shoots like this anchoring at the mouth.Does it bring the arrow closer to your eye for gunbarreling?

Going from shooting 3 under off the shelf to 3 under with an elevated rest won't bring the arrow any closer to the eye...BUT going from split finger to 3 under, raising your anchor point or switching from you index finger to your middle finger will place the arrow closer to your eye.

Ray  

Raising the rest accomplishes two things.  1) It allows the arrow the clear the rest better.  2)It allows exact positioning of the pivot point.

not just the rest for me, the combination has helped me a bunch. I see the point better , and the left , right line way better.