The Parsifal was Verity Audio's first speaker launched 30 years ago, and the rear firing bass has been a constant in most of their other designs.
With the Parsifal Ovation you can flip the bass around and have the woofer and bass port face forward. Why would you do this? You would do this if you had to place the speaker against the wall. If the bass unit is facing backwards (ie facing the front wall) the speakers need to be several feet from the wall. This feature gives you flexibility in placement options.
I recently moved my Parsifal Ovations to a second system where they are against the wall with the bass unit facing forward, and it works well and sounds superb in that particular situation.