@gm
I'm not a RhinoCam user, but I had a quick look at Mach3 version and can see that it would be easy to modify it to suit MASSO.
But when I was downloading the PP I noticed this comment on the down load page.
Please note that once you have downloaded a post, it can be easily configured and/or customized using the Post Processor Generator product available in both the free as well as the commercial versions of the software.
So from this it seems that a user of RhinoCam can create their own PP to suit their machine and controller.
Regards,
Arie.