I was just looking into the JASO MA rating and found a thread on Quora website stating to use Shell T5, but I think they meant T4 as it's 15W30 and has a JASO MA rating, the Shell T5 according to it's website PDF specs has a JASO rating but NOT -MA.
So going back to Quora site which suggestions is that we should use the thicker oil T4 (once again I think they mean T4 rather than T5) as it would protect better. If so the best part is that it's even cheaper than the T6 a whole $10 on 5 litre. Currently on sale for $25 for 5 litre so $5 per Litre Reg $29.99 or if you buy the pale which is 18.9 L for 79.99 it come to around $4.23 a litre!!
Just as I always suspected from the beginning, they even mention that Shell does not want advertise that these oils are JASO MA as it would compete against their own motorcycle oil that is prices higher.
Here is the Quora thread:
https://www.quora.com/Is-Synthetic-Rotella-T6-Oil-still-JASO-MA-rated-safe-for-motorcycles