Currently , onion skin can only handle keyframes (wiki.synfig.org/wiki/Onion_Skin),
it would be nice to have a pro version of onion which can handle each frame or at least each waypoint.
take a look at toonboom’s
toonboomcartooning.wetpaint.com/page/onion+skin
vtc.com/products/ToonBoomStu … wing/91081