The factor of flexibility is "additional" to the elements. The fact that the skaters can perform the quality element AND with MORE difficulty by adding to the difficult "flexablity" move. The straighter the leg in a Beilmann, the more leg "attitude" in a layback, higher extension in the spiral, etc...
With respect to the layback.....I find that too many skaters these days are substituting back flexibility for proper hip position/leg turnout. And the judges do not seem to be noticing (not that they apparently notice much of anything in the way of proper positions in spins these days anyway, but that's another rant.) Skaters with less of a back bend but better hip position are actually more impressive overall IMO — for example, Angela Nikodinov had a stunning classic layback.
