All 4 active weapon slots at the start (Borderlands: The Pre-Sequel)

only now I went through a story mission to unlock the 4th slot for weapons, I'm already 17
i.e. you cannot immediately open 4 slots, and upon repeated passage they will be opened

In principle, it is possible if you make separate saves where the task is already being submitted to receive a slot, but then you either have to give your saves to a friend so that he would come to you with your Persian and get a cell or turn on 2 copies of the game on one computer

And through config in any way?

Is it possible through the save editor?