I've seen the Forumula+ VOAs indicating it is a GL1 that tests as a GL3.
That is why I ran the 75w-110 diff lube, as it is close to the viscosity of the Formula+
(Diamond Chain also suggests a 50 weight oil in an application like the Harley primary)
My owners manual and service manual only mention Formula+ in the trans/primary.
I know HD says the SYN3 can be used in the Sportster trans/primary.
I did run that at my 1000 mile service. No UOA of the factory fill or that run of SYN3.
The Red Line Power Sports 20w-50 does have ~425 ppm of "moly" but it is also JASO MA rated.
"Blended with specific friction modifiers that are compatible with wet-clutches, suitable for JASO MA applications"
I may run that in my next trans/primary UOA.
I haven't seen information from Mobil that the V-Twin 20w-50 is JASO MA rated, I believe the 4T 10w-40 Mobil 1 is.
Both say "optimized" for wet clutch performance
I believe the M1 V-Twin 20w-50 has about 90 ppm of moly.
All the Red Line GL5 gear lubes are tested as 1A in the ASTM D-130 "Detection of Copper Corrosion from Petroleum Products by the Copper Strip Tarnish Test"
The Sportster Primary does have the stator for the charging system that has copper.
Eventually I'll do a UOA using Formula+, but I expect similar results