Now this is good thinking. I like to put a canvas bucket or strap or something around the front of the load to prevent unexpected javelins in a hard breaking situation. Just tie it back to your tie downs.I made a "rack" out of some spare 2x4s. The thickness of two 2x4s is perfect to get the lumber above the windshield and the bumps on the sport bar. The ratchet strap keep everything locked down and not moving.
I made the front cross bar 54" and the rear 53 1/4" so they tuck inside the plastic door surrounds with very little lateral movement during loading.