Why some materials don't preview on rendered mode in RH6?

Yes I am. Portability of the GH file is the critical issue for me, preferably without sending a Rhino file with it. I’ve tried everything with a text panel connected to the ‘M’ input and can’t get it to work at all??? Is that input nothing more than a well hidden right-click feature?

Hacking still required to make R6 useful after all these years?