I'm wondering if you may have already attempted the far less demanding, but often successful, commonly tried "folk fix" of loosening up the engine mounts and head steady just a bit, running at idle a few minutes, with maybe a little fast idling, and then retorquing everything back down to spec. This often ameliorates really excessive vibes by helping allow the engine to center itself a little squarer in its mounts and more comfortably. How many miles are on your Conti? If fewer than a couple thousand on the clock, I would definitely recommend trying it.