Once the piece was cured I removed the weights and peel ply and then cut all the foam off.
Here are some calcs and thicknesses close to what I will use for the top CS spar cap.

Ply   Depth Length BL
6      0.15    113
7      0.175  100
8      0.200   94
9      0.225   90
10    0.250   80
11    0.275   74
12    0.300   70
13    0.325   60
14    0.350   54
15    0.375   50
16    0.400   40
17    0.425   34
18    0.450   30
19    0.047   24

Test cap cured

Thicknesses marked out

Thin to thick