Switch to vulkan, I had to remove Lenny Simple Trainer and Outfit Changer, but keep version.dll. My game went from 30fps to 120.
EDIT: Forgot to mention that if you have any conflicting mods this can also happen. Like 2 mods that edit weapons.ymt.
I used unlock all weapons on 0.3 but I now have an invisible Repeater Carbine. I was wondering if there is a way to remove it, if you equip it you have to "untangle" the weapon by equipping another long arm and going back, making sure it isn't the one you switch to.