Finally managed to get past the last stuck point.
I'm somewhat pessimistically wondering how far away the next one is.
I managed to finish the wing arm and the membrane and was concentrating really hard on making sure that the membranes (which will be distorting the most) were as squared as possible and doing the best I could with everything else (inevitably the arms turned into rectangles including around joints where I really would have preferred more squares).
I'm really hoping that they'll work out all right especially if I throw multires on there. My head renders have got jaggies so that's what I'm anticipating in actual renders.
At least the stationary looks alright.