I am part of the "I run T6 in most everything" club.
As long as the bottle you choose says JASO MA on the back, it should be fine in the Pioneer.
Any oil stickler that buys Honda oil because Honda told them to, is ok with me. Companies spend billions of dollars per year combined to figure out how you get people to purchase products from them. Often times it simply comes down to brand loyalty, realizing we are not all engineers, and or clever wording aka trickery.
Manufacturers are allowed to suggest things, but not to require you purchase only their brand of fluids.
Excerpt from an Edmunds.com article:
"
"The OEMs are looking for protection and the customer wants longevity"
Potential warranty problems: The language in some owner's manuals suggests that using an oil other than the one specified by the manufacturer will void the car's warranty. This is not the case, says Thom Smith, Valvoline's vice president of branded lubricant technology.
According to the Magnusson-Moss Warranty Act, the onus would be on GM or another automaker to prove that a non-manufacturer oil damaged the engine. If dealers deny the warranty claim without first investigating it, they are in violation of the act, Smith says.
Consumers just need to make sure that any alternate oil they use is comparable in quality to the automaker's specified oil. Many oil manufacturers, including Valvoline, are so confident of their product that they offer their own warranty against engine damage that their products might be alleged to have caused."
What this says basically, is that even if we the idiot consumers are wrong, and we have a warranty claim denied for engine or transmission failure and the cause is determined to be the type of oil we put in the engine - the major oil manufacturers warrant that as long as you are using a comparable oil in your vehicle - they have your back if their product is determined to have caused any catastrophic failures.
With the buying power they all have, your $2,000 claim is hardly a drop in the bucket for them and most likely you will have a new (what ever you broke) if oil is actually to blame, and you used the correct oil viscosity with the correct rating for your climate, usage, and engine.
Now, with that said - as long as the viscosity is listed as being correct for your climate and usage, along with the JASO MA certification for wet clutch operation - the oil is just fine.
T6 5W40 still carries this designation.
The concern with oils like this used to be that they had additives like molybdenum disulfide. Newer additives like molybdenum dithiocarbamate don't negatively effect a clutch the way Molybdenum disulfide does. No major oil companies use Moly disulfide in their formulations anymore, they haven't for a number of years now.
In conclusion, I'm just an enthusiast that likes to read and be informed. I may very well be all wrong. However as long as Shell warrants the use of their T6 5W40 oil as labeled on the package for meeting JASO MA requirements, I will consider it safe to use in my machines that have wet clutch systems.
Stay thirsty my friends.