So, it's not necessarily pretty, but here's the first test of the 2D sprite rig in action:
I added a second isometric view of the rig so it was a bit easier to tell what's going on. The top left view is what will appear in the game.
So far, I'm pretty optimistic about this approach. It can have some pretty fluid and detailed animations, and still allow modders to create their own clothes, shoes, heads, and other parts without needing to know how to model or rig meshes. And it still allows for the pixel art aesthetic.
I still need to test it with normal maps and lighting. And hook it up to the actual space prototype, for that matter. But not a bad start for 2ish days of work!
And I'm excited to think what an actual animator and pixel artist could do with this setup :)