My main concern on using math instead of manually checking the P to V with light springs is the actual rocker arm ratios, instead of the advertised ratio
I've seen as large as a full + or- point variance(1.4 to 1.6 on a set of 1.5 ratio rockers ) on stock type ductile iron rocker arms and a little less variation on decent aluminum rocker arms
Test, test and test some more to be sure