Question Animation transfer for joint based face setups

Hey all.
I’m trying to gain as much flexibility with character animations as possible inside of unity.
Currently harnessing the power of the humanoid system for all body animation performances, which works fantastically!!
Then using blendshape face setups from maya to unity to transfer and share animation performances across multiple characters.
Basically for NPC I can have an animator controller that cycles through face and body performances shared across X number of characters at the same time. Very useful!!

However, we have just moved to the Quest and performance seems to be taking a hit. I am looking at switching to adult based joint setup for all characters. This was something that I tried before. But the facial performances do not share well!!! The animation is applied due to the same naming conventions, however, the positional data from one character to the next is different and either the face on the character the animation wasn’t created from implodes or balloons out as the joints are shifting to the characters face the animation came from.

Has anybody worked around this problem before? I would love to hear any potential solutions.

Regards
Benn