The Rules require that the lines cannot go farther aft than the root chord of the wing. Therefore some designs allow more slide angle than others. For example, planes like the Devastator with a straight LE and severely swept forward TE give you a lot to work with. With that fillet, you could get the leadout back to 45 degrees, no problem.
With any design, you can achieve a greater sweep angle by placing the leadout guide (at the slow position) more inboard. But enough is enough. You need some distance between the body and leadout guide.
I recently crashed a plane that flew OK, then I moved the guide too far inboard to try for more and found the limit.