Not to be a stickler but that isn't quite accurate. The knock sensors don't actually detect higher octane fuel. The PCM advances the timing until it starts to knock then retards the timing slightly. With Premium it can advance the timing a lot further before knocking occurs.
I don’t think Ford even pretends that they’re different based on software. They just call it 4WD for the same reason they call Escape a SUV instead of a CUV.
If you floor it from a standstill it will shift torque to the rear immediately even before the front wheels slip. It will also shift torque to the rear based on yaw sensors and steering wheel angle before slippage occurs. Its quite intelligent. Turning off TC probably defeated the normal AWD algorithm.
That article is comparing true 4wd systems not the Escape 4wd system. I don’t think there is ANY difference at all in the Escape and Edge AWD system. The Explorer system hardware is the same but I think it has different software settings for different terrain.
Did you check the owner’s manual. It’s normally no more than 10,000 miles or 12 months but the dealer is correct it will tell you when to change it based on how it’s driven - usually ends up around 7500 miles or so.
I haven’t heard of Ford denying claims for silly reasons or technicalities. It’s there to protect them from folks who legitimately abuse their vehicles.
Technically it can under certain very specific circumstances. But generally the mfr can only refuse to honor a warranty on specific parts that were modified or damaged by the owner.