I'm having trouble with the new mixing/blending.

My game script applies animation state data in the following order:

DefaultBlend :  { duration : 0.2 } ,  /*  Default must be first  */ 
Blend :  { from : "jump", to : "walk", duration : 0.400000 } , 
Blend :  { from : "jump", to : "run", duration : 0.400000 } , 
Scene :  { name : "idle", loop : true } , 
Chain :  { name : "chain1", 
   Scene :  { name : "walk", loop : true, delay : 0 } , 
   Scene :  { name : "jump", loop : false, delay : 0 } , 
   Scene :  { name : "run", loop : true, delay : 0 } , 
   Scene :  { name : "jump", loop : false, delay : 3 } , 
   Scene :  { name : "walk", loop : true, delay : 0 } , 
   Scene :  { name : "idle", loop : true, delay : 1 } 
 }

DefaultBlend loops over and applies to->from for all animations, plus it sets 'defaultBlend' parameter of the animation data.
Blend sets a specific blend time for to->from animations.
Chain is a sequence of animations that are applied in the following manner:

std::vector<SceneChain>::iterator itr = mSceneChains[aSequenceID].begin(), end = mSceneChains[aSequenceID].end();
 if(itr != end) // set the first animation
 {
     spAnimationState_setAnimationByName(pAnimationState, track, itr->mSceneName.c_str(), itr->bLoop);
     ++itr;
     mCurrentSequence = aSequenceID;
 }

 for (; itr != end; ++itr) // add the rest into the animation queue
 {
     spAnimationState_addAnimationByName(pAnimationState, track, itr->mSceneName.c_str(), itr->bLoop, itr->mDelay);
 }

And everything is updated:

spSkeleton_update(pSkeleton, theFrac);
      spAnimationState_update(pAnimationState, theFrac);
      spAnimationState_apply(pAnimationState, pSkeleton);

I'm testing on the latest spineboy example

I have read Set + AddAnimation Behaviour bugged? and several associated topics.

Question: What is the new method for mixing animations?