Snrub will chime in soon I'm sure. He is the resident GSF expert and VERY helpful. I have them also. You are up north so its a bit different for you from what I understand...not so bad in the south because of LMB pops. I know you can get sexed LMB...dont' know about in your area...but that would probably be a good alternative.
LOL. Expert definitely not. Drug into having to learn about them kicking and screaming more like it. GSF are a way of life in my neck of the woods. But Michigan................. way out of my territory. He needs some local advice.
I have mostly just learned to live with them (so far, the complete verdict like will not be in for another five years) and appreciate that they are feisty, tough little fish.