I have a Grace Pinnacle ... it has the metal all over the place and is grand on movement. (If I understand your question/comment correctly)
I am still kicking myself for not going for the Innova... and this is one of the reasons - - that frame has it all set up so that you can lift up the top and smooth under there, if you have to.
I cannot tell you the number of times, I have loaded up the batting, and part way through the quilt found it not responding correctly, and getting ruffly underneath. There was no way, short of stopping and unloading anything, I could fix it, since when do you notice it? When it gets on top of the top rail, out where you are sewing and your hand hits it.
If anyone has any batting loading tips on it, I sure would like to hear them. I would really like to be able to load my whole quilting frame by myself.