That's what I did to my Tac Sport. It increased the pull weight about 1/4 pound. I found a web store https://www.cz-parts.com that sells CZ sear springs in different thicknesses, .7mm, .75mm and .8mm, they are all supposed to increase the trigger pull weight. The factory thickness is .6mm, and the Tanfo sear spring is .635mm.
I'm considering ordering one of each to see what pull weight each offers, just haven't been able to talk myself into spending $10 per spring plus shipping from Czech Republic.