Well, it is really one of the things I’m looking for.
Yet, I’ll share with you a workaround that came to my mind. Not long ago, I’ve created an animation splitter tool which creates animations out of a single animation. I read all the information from an animation and just copy the keys I want.
What you can do is create a new animation, read the keys from both animations, add them together and divide by 2. Then, just use the animation current time to make sure you are on the same frame when you switch between animations.
Of course this won’t allow you to use a percentage of each animation, but it gets some of the job done.
Hope that helps.
This is the animation splitter thread if you are interested in reading the code: