Maxi or round ball. That day it was a round ball. I actually have two of them one I have set up with peep sites and I use the maxi in it. Use it for solo stand hunts. The other is traditional sights and I use round balls with it. Anytime we are pushing deer I use it.
I’m not an expert but from what I have read in order to maximize the load lifters you want the belt on the lowest rung it can go on. Then set the shoulder accordingly.