I would think this is an advantage for planar speakers like Maggies, the transducers are vertical panels (albeit with varying widths, down to the ribbons on some). Therefore it would seem the vertical dispersion window is much greater than with cones or domes.
But if you need to verify, try placing spacers no more than 1" high, first under the front of your bases, then under the back. See what you hear with the resulting changes in panel tilt.