Maybe I'm gonna do a complete fool of myself, but the latest pics of Sorceress, confirming fans' nightmares abourt her wings/arms, convinced me I had to explore what could have been a better solution for her arms.
Just to be clear, this is not fan art, but I'm using my original fan design to explain how the engeneering of her arms could have been exectuted to preserv full range of arms movement and no awkyard positions for the wings.

The original idea (see my albums in the signature) was to have a small hinge (those with a tiny metal bar inside) connecting the top portion of the wings to the upper arm piece. Those kind of hinges you see on many transfomers panels. But while this is a joke for Takara and Hasbro, I can't remeber seeing much of these on Mattel toys (I may be wrong though). Plus, the 4H made me notice that has to be ABS plastic to work, and usually upper arms are molder plastic.

The 4H had just glued the wing to the upper arm with a almost 45° angle, but stuck in that position, still better than what we got, but maybe there was a even better solution

Okay, so the point was to replace that tiny hinge with some sort of rotating articulation that could allow all positioning of the wings while preserving the same "fan" contruction that opens thanks to gravity when the arms are rised.
The solution could have been making the upper arm a rotating drum that house two pegs from the shoulder piece (this time with a flat cut) and from a separated ellbow piece
The upper part of the wing and dis middle-arm piece are one solid piece. The wing is not coming straight from the center axis of the arm, but is more on a tangent (as shown in the section below).
I think there might be some size issue since the arm is so tiny, but I don't think this is impossible. And it would have allowed full range of movement for the arm, whileallowing fans to keep the wings in a much better pose all the time by simply adjusting the rotating middle arm portion.