I think the light strikes is more likely either inadequate striker protrusion, or drag on the striker as it moves through the hole in the breech face, and not the spring.

And by the way, a spring with the same wire diameter and material and four more coils (more turns) will be WEAKER and not STRONGER. However, if the spring is too short it can cause a problem especially if there is drag in the striker.

My Kahr had light strikes and eventually they replaced the whole slide. I think these Kahr pistols have a design defect or two and one of these days Kahr is going to have to address it in an expensive manner. For the time being they seem to be content to band-aid it on a case-by-case basis.