Also right now blendmodes are now supported (but I believe alpha is).
Keyable draworder is there but is not working properly and is reported as a bug.
FlipX, FlipY are not supported atm but are planned in a sprint soon enough. Actually the whole rotating/flipping a spine object within Defold is being looked at and will hopefully have a good solution.
I remember we worked with manipulated bones previously (or at least the gameobjects representing the slots). Just don't remember what the outcome was. I will need to dig into that.
Animation blending is supported but not in several layers.