After building lots of resin kits over the years, I became committed to rigging with non - stretchy monofilament thread passed right through the wings and glued under tension. Just like the real landing and flying wires, the mono anchors potentially saggy wings rigidly - and, I happen to think, more visually in scale using paint blobs rather than AM turnbuckles (IMHO, sorry, Bob).
I've thirty year old heavy resin wings that haven't sagged a mm! (and mono helps add a little strength to WNW's famous wobbly undercarriages!
FWIW, Sandy