I would advice you to make the maximum amount of build slots be closer to 30 than the current measly 5. This will be in your own self interest in terms of ludology, since I believe it is your interest to have players experiment with the different builds they can, and if you wanted a monetary incentive, more slots lead to more opportunities for players to go: “hmm I want to customize my build 15 so that it stands out from the others” which leads to more sales of cosmetics.
Just expand the amount from 5 thx.