I wish I could remember where I read the following information about the D9patch technique, but it seems like it might add to the discussion.
They said that when you cut the nine patch in half on both of those directions, you have in effect created a patch with a sashing and cornerstone on it.
I may be the only one who needed to be told that was the effect of doing those two cuts on a nine patch, but it really made a difference in my mental picture of the block - - and the possibilities.
I may have control issues which is why I enjoyed that little fact <g> but on the other hand - - I am also fascinated by lava lamps, so ... the simple things really keep me entertained <g>.