Yeah. I got it working. Thanks @cnoellert and @hBomb42 and @philm
After getting An expression exists on a parent or a child. error over and over again I started a new action and my eval expression was getting its values from another action with the trackCam and the TW values from the Timewarp.timing.
I was even able to TW the alembic proxy geometry animation using this technique. I’ll export the FBX camera for 3D but do you know if it would be possible to sent the geometry back out?