The issue with close targets is the splash comes off at 90 degrees, and then can bounce off other surfaces further, like ground. If that target is angled to the line, then there's a possibility of the splash coming back to the line rather than out sideways and thus along it. If there's an edge or feature on the plate, that can change the angle of splash.
If you want to test it, stick an 8yd target in a white paper tube and fire 50 shoots at it... you'll soon see the effect.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep