Layered blend per bone - frame of animation?


I got a question about the layered blend per bone node. I’ve used it to blend hand animations, using a fight animation. What i’m wondering is though…what frame of the animation is used when it blends? Because the node has a beginpose, an animation and a blendvalue. What if the animation used has his hand opened at the beginning and closed at the end. Does it always blend the beginpose to the ending frame of the animation? For example if my blendvalue is 0.5, from the docs I get that it blends halfway to the animation. But what frame of the animation is used? Is it always the last frame? does it also depend on the blend value; so if your blend value is 0.5, it blends halfway to the animationframe halfway through the animation, so only 0.25?

I hope my question is clear enough, let me know if it isn’t…