I'm working with the tutorial that comes with the Jackie EC, which instructs that when fanning the bellows, the lower front edge is the side that should stay closed. I tried to do it this way, but the awkward angle caused a great deal of stress to my thumbs and pinkies. Pulling forward on the thumbs made it hard to keep them in the straps, which led me to compensate by pushing hard with my pinkies into the curved ends of the plates.
Seeking some relief, I tried keeping the bottom edge closed instead, and it made a world of difference! I can play as long as I want now without discomfort and with no need for my pinkies. The bellows practically work themselves.
Of course I think it's good to be able to practice longer, but am I setting myself up for problems later by using the bottom axis instead of the front axis?