Actually also curious if the most recent octane and ue 5.1 works with metahumans? If not I might have to use a different character creator.

Cause this is what I see when I tried all the steps:

https://imgur.com/jNl21ct

Yes, there are two ways at the moment.
You can export your cinema4d scene to orbx.

Then you can import the ORBX as a proxy into the scene. This proxy can then be placed into an unreal scene as a sigle entity.

Or you can import the ORBX. The plugin will then attempt to convert the ORBX scene to ...

The easiest way to do it is to export your c4d scene or parts of it as an ORBX or animated ORBX file.
In Unreal Octane just import it as "ORBX scene as proxy".
It works very well for me and you don't have to tweak your materials again.

How do I setup a ORBX as a proxy in unreal?