Hi Fettness,

I'm not aware of any default solution for this. Nor has anyone ever asked in the past ten years to connect this rig with MoCap data.

When you check all the FK Joints, the number of Constraint Tags that rule over those would prevent using them quickly.
IK and FK are the feed for the Bind Joints, meaning that if you need to overwrite anything, that would require a lot of change.

Using only the Controller to transfer would also not work. So, creating that definition would be a lot of sorting through. Yet, again, the typical Motion capture would not provide all the needed information to run it. Which leaves a lot of manual work along the way. I haven't seen a MoCap from anyone here that would contain all the details, which is even more valid for the Toon rig/character.

I can only suggest opening a ticket with the needs that you have. "Share Your Ideas"
https://www.maxon.net/en/support-center

Sorry, that is all I can do.

My best wishes