I really love the idea of allowing the loom to take what it needs of the weft yarn. I do beat on an open shed and it works very well for me. My issue has been that I have enough drag from my boat shuttle bobbin that it pulls in the edge warp threads if I don't hold onto them while I am pulling the shuttle out to the side.
I am extending my arm straight to the side or even away from myself, so that shouldnt be the issue. It is not the bobbin being overloaded because it happens no matter how much yarn is on the bobbin. On my first project I was using worsted weight yarn so I figured that was the whole issue. For the second project my weft yarn was just finer than the 8/2 rayon I used for the warp. It was a little fuzzy being a merino, yak down, and silk blend. I have been winding my bobbins tightly and evenly with my cordless drill acting as a bobbin winder.
What else can I do to get the flow like Jane does? Do I need to have more tension on my warp? Is it because I have been using troublesome weft yarn and a different weft on future projects will flow with less drag?