The character's file has some actions to control a rig (rigify) this works fine in the NLA but shape keys need to be controlled by a mesh. A setup like this:
Even the offset (start keyframe) can be adjusted.
The scene which links to the character's .blend has a proxy for the rig, actions work fine. But I don't get the key-track from the above image.
When I add another proxy this time for the mesh instead of the rig another instance of the character is shown. The 2nd instance isn't animated by the rig but shows the shape key animation!
What is the correct way to get a key-track in the NLA?
(This is a follow up of: How can shape keys of a linked object be controlled? but after some reading I focus on the NLA tracks.)