How can you transfer shape keys to a Mixamo auto rig with your character?

[joseph]

Mixamo loses shape keys. Can this be prevented?

Not through Mixamo…as an option…but one way would be to keep one version and send to Miximo, then after you add the armature on export, export without skin…then on your saved copy import the new fbx. and parent to the mesh…another way is to open a new blend and import the fbx rig, then save as a blend file then new, and open your original, and append the rig you just saved…still have to add a armature modifier and parent the rig.

Transfer Shape Keys animation blender 2.8

Blender Pipeline #4 - Combining Facial Shape Keys & Armature Animation in Blender with Auto-Rig Pro

Check those out, they seem to have solutions