Not a P10c expert and certainly not knowledgeable of
all the mods, BUT...
Because a springs rates out at 13 lbs in one gun doesn't mean it will be the same in another. Spring pressure comes from many factors, including
installed length. Then, when making substitutions like this, you also need to check the compressed length to look for '
coil binding'.
When the coils of the spring are over simply compressed or actually rubbing, the spring can fail prematurely with no warning, which would disable your pistol. Murphy's Law predicts that would be at the exact point in time when you need it the most.
If
Wolff Spring doesn't have reduced springs, then I think you'd do better to simply trim off a stock spring, in 1/8 turn increments.