My speculation, but here‘s why I believe that the graph does change with +
The chart is titled “ZO PULL - A/B/C - NORMAL” (does not reference +)
Notice on the chart, that the leading edges of the curves all line up for the A’s, B’s, and C’s. This would correspond to pull (response time) values of A=0.3, B=0.6, C=0.7 (higher number = faster response).
The pull values for A+/B+ and C+ are 1.0 and 1.4, respectively. Therefore, my assumption is that the + curves are all shifted to the left with respect to the normal curves. At least that’s my logic…