A bug fix is going to be enabled tomorrow which will make animation poses, with a weight of zero be ignored when the animation plays. This is specifically pose weight, which is separate to the weight of the animation as a whole.
Currently, there are poses which are simply in the animation as parent containers for child poses. These parent containers have a weight of zero, and should not act as keyframes. They are currently being treated as keyframes, which sometimes makes them animate when this is not the intention. This change will fix that.
After testing this change with the top 25 games, and games in the featured sort, we do not anticipate any issues. Following the change, which will go live tomorrow, please provide feedback if you experience any issues in your games.
What is weight used for though