I think that its pretty much trial and error. You have to pull the trailer and adjust accordingly. Hopefully, since the trailer came with the sway control it should be adjusted fairly close to where it needs to be.
I have the same anti sway and have found that tightening until it gets a little hard to turn then give it one full turn after that works for me.
If I do it up too tight it pops and bangs as it moves in and out.
Another thing to remember is to always loosen before making tight turns when parking.