You are correct, and some speculate that the 08+ inclusion of piston oil squirters may also be a reason these seem to be worse than older years. However, I think the low tension oil rings inherently play a part as it appears a fundamental aspect of low tension rings is that they are super thin to reduce surface area and thus friction, which limits the area the oil can pass through and the size of the drain holes. From people who have done the piston swap, they report that the drain hole diameter actually does not appear to be any bigger, but they are positioned and angled differently. Do agree that the only way to truly solve the problem is new piston and rings, im just trying to keep a log and glean any knowledge with this thread, as most threads with this topic seem to be full of one time anecdotes then we never hear how things went going forward.
Speaking of which, I have an update. I checked the oil at 401 miles today. The dipstick read approx. 75% to 80% between the min and max lines, and I slightly overfilled during the change(1mm or less on the stick), so about .3 quarts for 400 miles. That works out to a quart every 1333 miles. Last run I added 2 quarts during a 2.5k miles OCI and it had 3.5quarts(out of 4) when drained, so around 1 quart for 1k miles on the dot. This is way too early in the OCI and too narrow a margin to be conclusive obviously(future oil degradation effects, bad reading etc), but its a decent sign. Ill keep monitoring everytime I fill up on gas. If it holds for the entire 4k OCI I have planned, Ill switch back to valvoline FS HM 0w-20/5w-20 and see if the results are from the 0w-40 M1 oil or the sketchy engine flush. Not a perfect expiriment, but thers anecdotes out there that 0w-40 is the ticket for 2AZ, maybe we can get a better idea.