Anecdotally: The Mobil 1 4T Racing 10W40 I've been running for 3 most recent OCI's is JASO-MA and API SJ-thru-SN rated, and probably a recent product (purchased this past spring) shown by the diminished additive package in the UOA on the UOA board. (but it did wear better than average based on staying in grade, insolubles levels and wear metals, on the Blackstone UOA, FWIW.
From the Japan Standards organization point of view: for more recent JASO-MA does the oil manufacturer have to distinguish whether it's an MA1 or MA2 (none of the 10W40 I used spelled it out on the bottles)? Which certifies wet clutch/ shared transmission (and water-cooled^) for the motor oil. Can it be both MA1 & MA2 at the same time? How long has there been a difference in the standard?
As for the 20W50 V-Twin, isn't that formulated for air-cooled, dry-clutch, not-shared transmission format bikes? (such as Harley & some older BMW motors) So would they allow non-rated motorcycle specific oil to have higher FM levels that might cause a wet clutch to slip... So who uses the M1VT in their shared sump bike?