I think having you building a tweener on GoAsap would be absolutely great for advanced tweening capabilities. I'm not really worried about having more Kb for a library and I'm sure it won't be that much. The job you have done on your Tween family is really good, especially in a real work process, some properties has been just really thought, such as delay increment or similar.
Instead of changing the TweenMax, why not build a TweenMaxGo (there's already a TweenGo I think)?
Everyone would be happy choosing what they need between Tweenlite, TweenMax and the Go version. Moses has done an amazing work on his engine and having you develop a parser on it would be IMHO The Tweener to use.
