Of course the Falcon has 3 masts. My hunch (and I admit it's only a hunch) is that the DynaRig concept lends itself best to multi-mast designs. For a single mast I would prefer a more conventional sail plan.
I think a major factor holding back the multihull motorsailers is that they are not self-righting. Find some way to overcome that issue and bingo! The demand for multihulls would start climbing.