Shape-key groups

Hello. It would be great to have the ability to organize shape keys into groups and sub-groups. This would help keep things more organized and manageable and unlock many more functionalities. For example, it would allow for having relative and absolute shape keys on the same mesh, at the same time, by assigning one group of shape keys to absolute and another to relative. Additionally, if several shape keys need to be turned on and off together, the user could simply change the value of the group those keys are in.