I am using that combination frequently without problems.
Most of the time this combo is on a tripod. When hand held, I typically hold the Kirk lens foot and try not to support all of the weight with the camera alone.
When shooting hand held I stabilize the lens by holding the foot and locking my left elbow against my body which provides good stability. In portrait mode, I simply loosen the collar to turn the camera around and use the same technique.
With a little practice, you will love this combination.