Maybe this would be better?
The whole thing is cut into three parts, some overlapping parts can deform in the same way as long as they bind to the same bones with the same weights. This allow some folding regions to overlap which would make things easier (for the sharp angle). The edge of the overlapping areas could use a little fade out to have better transition, if they do not deform in the same way.
This is how I am doing it now. I am also looking for a better way to handle these kind of blending.
If anyone have better way to improve, please share.