IDZRVIT:
As you noted, 280 is the line you're not supposed to cross, even according to the service manual. We're not complaining about being able to reach 260 at all, we're complaining about how relatively easy it is to reach 260, and how it obviously keeps on rising well past that if pushed. If flogging this car on the track or street resulted in temps that barely spiked to 260 but never went over, there would be no issue (although some would want to run a cooler anyways just to keep the oil colder, more on that later).
But as it stands, it's clear that track conditions will push a stock car smack into 300F and limp mode, and even aggressive street driving can walk right past the 260 mark if you let it, which means 280 will happen if you're not paying attention and/or driving in hotter weather (or on a mountain road, etc).
Even given the 280F standard of the service manual, the car's oil temp performance is at best subpar, and shouldn't be on a car that's advertised heavily to and supposedly built for enthusiasts, and touted at Nissan press events where they track the car and try to convince everyone that it's trackable.
Back on the point of temps though, just because keeping it under 280 keeps you within Nissan's acceptable range and keeps your warranty fine, that doesn't mean it's optimal for the engine. As oil temps go up, regardless of engine design the oil itself suffers. The hotter the car gets, the shorter your drain intervals need to be, and the less effectively the oil will be able to do its job. From the perspective of maximizing the health and longevity of your engine, 'anything under 280 is fine' isn't really acceptable. The math works out fine for Nissan, as very few drivers will do it enough to break the engine before the warranty runs out, and the few that do can probably be denied for one reason or another, but that doesn't make it ok for us from an individual perspective.
Edit: in case anyone's wondering whether I have a split personality... I do this with everything in life. It's not uncommon for me to argue both sides of a debate back and forth
