Nah, I use 10-12lb fluoro for most of my squarebills, especially if I’m trying to get a little deeper down. I’ll bump up to 15 if I’m in some especially gnarly cover but 12 will handle most of your uses.
Not sure why fluorocarbon or 12lb. test. 4 works great in light cover (rocks, soft veg.). 30 lb. braid with leader works great in heavy cover. What are you fishing in?