I agree emphatically with Del. I spend extra time to do my best to establish accurate width profile, thickness, taper, facets, and only push against the floor a couple of times. I want to see just a few inches of movement by pushing pretty hard, then that's it, I'm off to spend my time on the tree. Sometimes I may push each limb against the floor just once, sometimes not at all.
On the tree with the string longer than the bow, you'll stress the limbs no more than by floor tillering. Besides, I prefer the view on the tree where I can better see it, and see the limb's strength relative to one another. I'm big on syncronizing the limbs, the earlier in the tillering process the better, and I'll learn almost nothing about the bows relative limb stength by floor tillering. Put it on the tree and I know precisely which one is stronger and needs worked first... I know with just 2-3" of tip movement.
I too used to spend too much time floor tillering. My bows would more often come in under weight, and I think I was mostly wasting my time. ... or maybe I'm just no good at it