A good friend of mines struggles with the brake setting as well. Like you did he brings up the trim to just start the prop to spin. However my plane I actuallly have the brake set at 90%. And when power is applied and not spinning you can just move it by hand and hear the brake work. I have an OS 110 hv esc and plettty motor. Point is you might consider a higher brake setting and have your trim set just below the prop spinning.
Also so my friend just moved up your way. Tim Pritchett. Hopefullly we will see you at one of those contests up there.