>>10155429>Articulated wings do have additional parts but the amount of space it takes up in a mold would likely actually be lower, since it will likely be 2 more or less flat piecesSurface space on a mold is limited.
So while it's cheaper to cut the mold for something flat (cavitation costs increase by who knows how much), wings take up more space than thighs or arms, which means they'd likely need to use another mold.
Adding another mold costs much more than just the cutting out more depth by a lot more. A single mold can cost 15k-40k, whereas just drilling the mold is in the hundreds to very low thousands.