I live in a brutally hot climate & I run 15w-40 in trans & engine.Keep in mind that "transmission oil" in the 650 means just the lubrication for the set of reduction gears after the CVT/clutch and before the final drive unit (which uses 90W hypoid gear oil).
Not sure why you'd want to use something with higher viscosity than factory spec (10W-40) unless you live in a brutally hot climate.
I just assumed that it would extend the life of the transmission. But it does appear to contain a lot of Moly. I will just stick to the 10w30. thanks