I've been trying to get better braking from the JP brakes on my F-16XL. At first I was using only 2S LiPo batteries for brakes and had almost no braking power on pavement. I went to 3S LiPo using an ASSAN AG63 and it was much better but the brake output from the controller failed. Now I am using the JP brake controller on 3S LiPo and it is OK but not as good as the AG63 on 3S. I'm using 100% travel on the Jeti for brake control. Good luck. Let us know if you find a working combo.
Gary