I suggest you try what worked for me when I had a similar problem. (1) Set the Almen block and strip so the spray pattern hits the center area of the strip - measure the arc height. (2) Peen another strip of which you peen the center and then move sideways and peen one end and then move the other way and peen the other end. Compare arc heights of the center peened strip with the fully peened strip. If they are the same, just use that system. If the center peened strip has a lower arc height, use the ratio of arc heights to compensate - record the ratio as a "Shaded Strip Compensation" - That should satisfy an auditor.
Pete Bailey
