The adjusting screws set the tire & sprocket in a left or right direction plus set the belt tension. Adjusting the right screw clockwise in (pushing the right side of the tire/sprocket to the rear) to move the belt away from the rear flange. Tell me how this would be different than adjusting the left screw counter clockwise? It has to be a balance to get the tire running straight with the desired belt tension & locating the belt on the rear pulley to the desired distance from the flange. I can't imagine how turning either screw would not effect either the tension or alignment, provided everything is straight---it's a both screw adjustment--unless the adjustment is minor & doesn't effect tension or alignment out of desired setting. Just my 2 cents worth.
Darrell