Thanks, I don't know what I was thinking, being able to still do MR, but somewhat painlessly by booking reasonably priced AA operated and upgrading to business.
Seems like I either buy a more expensive AA flight and hope to get a business upgrade, and still earn less mileage, or go with a cheaper partner airline and get more points (and let go upgrade).
From cumulating miles perspective, the 2nd approach seems to make sense, but just more painful...
One has to be careful especially with higher class JAL flights where discounted premium economy and discounted economy fares have no cabin bonus and only credit at 70%.
That being said, one doesn't have to completely give up on the idea of upgrades as Jal frequently sells day of departure upgrades, but only when the flight is sold and operated as Jal,
not on code share flights.