That's the only adjustable bracket out there I know of. The gap is a big part of the reason the system works. The screen is not just an air blocker. That creates turbulence in the rider area. The gap allows air under the screen to flow up the back of it into the low pressure area created by the air at the front of the screen going over the top. Air flows up the front, up the back, meets at the top and flows over the rider's head.
If you don't mind the possibility of potentially needing to place a second order, I would suggest getting the Madstad bracket and using the stock windshield. That was enough of an improvement for me to forget about buying a new screen.