Houdini and Unreal workflow for animation?

I want to try combining Houdini and Unreal for animation.
Using the render speed of UE for most of the scene and Metahuman, but incorporating Karma renders when necessary for their quality.
Have a couple questions before going in if anyone has experience.

Can UE output proper AOVs for compositing with offline renders?
Do USD scenes/assets work well between Houdini and Unreal?
Does MaterialX work between them?
Any major issues to be aware of?