Thank you for the feedback, it's very helpful! I adress a lot of these issues and bugs in the next version. But one thing is new: When you choose the upgrade, do you use a controller or mouse and keyboard?
Oh and meta progression is on it's way. I started to put in the variables, but the UI is so much work haha. Another thing I planned is to combine weapons when your slots are full and picked up some sort of upgrade item.
The new update (I hope later today) has active weapon triggers on controller buttons (A,B,X,Y and 1,2,3,4 on keyboard) and maybe an option to make the trigger automatic.