Hi Alex,
Yes, to know this system will undoubtedly be well-invested time.
I have done a complete series about it, but it was more to expand its use into Motion Graphics, or other complex animations, to have the main weight on art direction, instead of to technical director work. Yes, that needs some prep, but then the fun parts start, and it should get better the closer the deadline comes.
Here is the series:
https://www.cineversity.com/vidplaylist/animation_techniques_for_teams/animation_techniques_for_teams_part_01_course
My main idea was here to use a specific hierarchy, which can be designed in any way but must be kept after that. This allows us to work in teams on even very sophisticated animations, and adjust otherwise keyframe monsters with ease.
It doesn’t focus at all on character animation!
A series about the Animation Clips and Motion System is here:
https://www.cineversity.com/vidplaylist/mixamo_to_cinema_4d_character_workflow/mixamo_to_cinema_4d_character_workflow_series_introduction
You might find that he does something things differently than I have suggested in the past, e.g., placing Mixamo joints under a Null, then create the clip. He does it with the first joint. Anyway, both ways are working fine.
Kai did a tutorial on Animation clips (relative/absolute), but I can’t find it. Sorry about that. I hope my little clip helped.
All the best