I don't have Dynastats at the moment, but thanks for passing this along for other owners! It's an easy enough tweak to try out. I never would have thought of it, though, so appreciate your taking the time to post.
I know this thread is a few years old, but I thought I would add that I experimented with the same thing you did, but with Apogee Duetta IIs. I experimented with connecting the Bass and MRT ribbons in phase and out of phase. Like you - out of phase worked better in my room. It was a very small room for these speakers (12'X14').
I remember in the old days (early 90s) we could blister the paint off the walls with a set of Dynastats and our M-60 amplifiers, which played a lot of authority in the bass at the same time.
Later versions of the speaker had the new toroidal transformers, which had a crossover that made the speaker hard to drive with tubes. But there is a fix for that, or you can use a set of ZEROs, and its no worries. The speaker is not particularly power hungry IME.