I also have a 2012 S Hybrid. Currently 168k miles on it. I had a phase where I was burning a quart of oil about every 2-2.5k miles for a while. Dealer said almost exactly the same thing. Then in the last year or so oil burn slowed down considerably to 1 quart every 4-5k miles. Turns out there has been a big change in the type of driving I've been doing.
During the high oil burn phase, I was doing a lot of long distance highway driving, where I was cruising around 85mph for long periods of time. Oil temp would run 217-224 depending on traffic and air temps. Now that my driving is mostly local, even if I push the car hard in Sport Mode, my oil temp sits down 205-207.
New independent Porsche mechanics I use, who are big on the Porsche Rally Car circuit, say that the higher engine oil temp for extended period is causing greater oil vaporization. The explanation seems logical and my spark plugs were all in excellent shape when last changed.