Definatley walk back.
If you want to be closer to begin with take a bow square, hold the extension against the riser, with the T portion horizontal mark the center of the arrow with a marker.
Flip the square to the other side of the bow, if the arrow is centered on the mark you have it square.
If its not move your rest so it is, and repeat till the mark on both sides is the same. therefore the arrow is going parallel to the riser and is at "centershot"
then do your walkback tune, its required.
Walk back tuning to set the arrow rest position (centershot)
AND then,
set the sight windage (horizontal position of your pins or lens)...
Hang a weighted string from a nail on a target.
Stick a round sticker on the target face so that the string splits the sticker. Use your existing 20-yd pin, step back 20-yards from the target and fire at the sticker.
Don't worry about where the arrow hits.
Walk straight back to 30 yds, and using the same 20-yd pin setting,
fire an arrow at the sticker.
Repeat at 35 yds and at 40 yds, using the 20-yd pin and firing at the sticker.
If your arrows look like this pattern " / " or “\”,
then pick a direction and move your arrow rest 1/16th inch.
If the pattern gets straighter (more vertical), then that is great. Keep adjusting in that direction.
If the pattern gets more crooked, then adjust in the other direction.
Keep firing arrows and keep adjusting the arrow rest position until you get a vertical pattern of arrows.
Eventually, your arrows will hit in the target is a straight up and down line like this " | ".
LOCK down the arrow rest setting. Your centershot is perfect.
But, your vertical pattern of arrows may not be hitting the string.
The vertical pattern of arrows may be on one side of the string.
Let’s say the arrows are say 6-inches to the left of the weighted string.
Pick a direction to adjust your sight ring windage. Adjust the sight ring windage 1/16th of an inch. Repeat the test. Fire arrows at least 3 distances, and see if the vertical pattern of arrows gets closer to the string.
If the vertical pattern of arrows is getting closer to the string, then that is great. Keep adjusting in that direction. If the vertical pattern of arrows is getting farther away, then adjust in the other direction.
Eventually, you will have a vertical pattern of arrows right on top of the string.
Lock down the windage and lock down the arrow rest. Windage and center shot are now perfect.