As I use it mostly for game development especiately mobile/VR, the rig is quite complex. I would appreciate if there will be some toggles or something similar to hand fingers, where you can select 0. These are the areas that I think could be simplified:

Foot fingers - add option to have just foot represented by just one bone instead of five
Head - for game characters that are not so close to camera, the facial rig is unnecessary. It will be nice to have it optional.
Breast - I see that ribcage bone is beneficial, but I could imagine that linked breast bone could be optional


The last thing but not the least, I would like to say big thank you to the developers.