2 root bone setup fails using MechAnim Human, works in generic

I'm using two 2 root bones to precisely control character position. The root bones are marked by "stars" the bigger is root 1 and smaller is root 2, a child of root 1. Hips are child of root 2. The "Motion" > "Root Motion Node" is the same in both examples. This is how it looks if I set it to "Mechanim Generic", this behaviour is desired and its identical to what I see in animation software (Blender).

When I set the very same FBX to "Mechanim Human", the root 2 fails to move:

 

Might be a long shot, but is this behaviour linked to this:
"
In-between bones
In many case, skeleton rigs will have more bones than the ones defined by the Humanoid Rig. In-between bones are bones that are between humanoid defined bones. For example, a 3rd spine bone in a 3DSMAX Biped will be treated as an in-between bone. Those are supported by Humanoid Rig, but keep in mind that in-between bones won’t get animated. They will stay at their default position and orientation relative to their parent defined in the Humanoid Rig."
http://blogs.unity3d.com/2014/05/26/mecanim-humanoids/

 

Ideas anyone?

 

Devs?

 

Exactly, you cannot have translation animation on in between bone for Humanoid avatar.In this case you need to use a generic rig.

We cannot retarget non human bone animation from one avatar to another one in a generic way because the bone may not exist on the destination avatar.

 

Hmm, Ok thanks! Now I understand MechAnim Human way better; optional root bone > Mechanim human bones > what ever additional bones I want to add.

 

Yeah, a really, you only have 1 rootbone. You are just moving the wrong bone. You need to move the actual root bone. I do a similar set up, but for a totally different reason, mainly IK.

I recently did a video on the root motion topic, but it also a product promotion.