I am not a lefty, but left eye dominant. When I first got my machine I really tried to pantos from right to left, but just couldn't do it. 3 months I suffered. Then I tried it left to right, with great success. I attended an APQS road show near by and asked if this would hurt my machine. The team assured me I would be fine. I have been quilting for 3 years now, on the front of the machine from left to right for custom quilts, and on the back left to right for pantos with no problem.
I sometimes have to pay close attention with panto patterns regarding the direction of the design, but other that it has been smooth stitching!