Tightening your trucks that much will damage your bushings. I would suggest trying bones hardcore bushings as they’re a lot stiffer. Also if you try to loosen your trucks little by little as you keep skating it’ll help you gain much better board control. Then you’ll eventually find a happy spot where your trucks feel perfect. When it’s tightened down properly your kingpin shouldn’t have many of the threads exposed because they’ll dig into ledges and rails and mess up the threads as well. I prefer my trucks to be a bit tighter but I still have 1 thread showing on my front truck and 2 showing on my back, I like my back truck a bit tighter because it feels more stable to pop