Yeah, I wish floor tillering worked better for me. I just have a hard time getting it to look and feel right. Once in a while it would work out for me, but I had so many bows messed up before they ever got to the long string.
Now, funny enough, when I do Mollies and such, and sometimes shorter bows like recurves, I can "floor tiller" by putting my hands wide on the limbs and pulling in a rowing motion with the handle against my knee. For some reason, I can both see and feel the weight (approximately) and the balance of the limbs like that, no problem.