I think the "barbell" dampeners were put there because they could fit within the wheel space. The larger dampeners have more of an effect on harmonic dampening - greater range. The downside, as it turns out, is that you can't put 18 inch wheels on the car (winter tires and wheels). My ride doesn't use the bigger dampeners so the MODA wheel does actually fit without issues.
I'm thinking it's a sort of band-aid. It wouldn't bother me in the least whether I had them or not.