Replacing the Humanoid Rig or supporting Animation rigs as primary

When Animation Rigs were first shown I knew this video was the ultimate goal.
I watched most of the video tutorials and was pretty impressed (And disappointed by the use of bloated GameObjects)

As someone who continuously suffers to get humanoid rigs working properly in unity, I immediately tried to figure out a means to store my motion in rig space like in this video. But it isn't immediately obvious
Right now I am exporting targets to global space in FBX to use as ik targets. I wonder if in the future we can have an importer do this auto conversion. especially since Kinematica would also rely on some global space bone data