The V-start to which the OP refers is a 650 cc v-twin that is not known for excessive heat (or power, = heat). That engine has been made for decades in various forms; if it were a true problem it would have been heavily revised or discontinued by now.
In fact, I doubt that engine gets any hotter than the turbo housing of any of today's diesel engines, and yet dino oils survive there quite well.
kmrcstintn, you are way over thinking this ...
ANY quality 15w-40 HDEO conventional oil will do just find by any OEM OCI in your application. There are plenty of UOAs in the MC section to show this. They survive just fine in all kinds of air-cooled applications and protect the equipment very well. Many of today's HDEOs would likely pass the MA standards, but that is not a market they choose to target. Regardless, many of us use dino HDEOs with great success, and no adverse problems.
I could not find a recent VOA/UOA of the RP you seek (I only went back about 5 pages, though). If you want to know how much moly is in the RP, then you have two options:
1) ask them
2) get a VOA and have it checked.
You might WANT an ultra-expensive syn; you don't NEED it. Nothing wrong with that. Just don't try to rationalize or justify it with erroneous logic.