I recently attended a seminar from Meadowlark designer Pat McGinty, and he says that the sloped baffle isn't all that maintains time-alignment. The slope is to keep the sound-originating (ok, so I can't recall his exact words) points of each driver on the same plane, so they're equi-distant from the listener's ears.
From my understanding, the simplicity of the 1st-order crossover is the major contributor to the time alignment. For more info, check meadowlarkaudio.com
From my understanding, the simplicity of the 1st-order crossover is the major contributor to the time alignment. For more info, check meadowlarkaudio.com