I Just started using Maya and yes the Arnold material system is a “challenge” .
However I would not expect Autodesk to be bothered with providing a solution for converting CC4 textures to Arnold either as they are not the party claiming import compatibility with Iclone/CC4, it is Reallusion who is claiming & advertising export compatibility with the major 3DCC’s and game engines with their export presets.
Also USD to Maya is not a good solution if you want to have fully editable animation rigs in Maya as we have with FBX import