I don't have the answer but have thought about same issue you are posing about...and then my new LCp custom this weekend had me rethinking this... I had shot a friends older Lcp, prior.
I don't have any thing scientific to back up my feelings on the new gun but I kind of thought the fatter new trigger on the custom was easier on my hand pulling the trigger and during the shot.. I went into the range expecting the same feeling and found it to be less. anyone else feel more control and less snap for that reason?? not trying to take away from spring question.. I think I read wolf has several different rated springs rated less then 13,, if you didn't want to go that high. If any one adds any input on the trigger helping , I know I've seen them also as a orderable part.
I also tried a few different brands of ammo,, I noticed a difference with American eagle feeling less of a recoil.. maybe for range shooting look for the underpowered round?
good shooting.