You don't have to "tear into" it to try a fresh oil/fuel mix to see if it's noticeably spitting out less oil after a few minutes of using it. If so, it's then NOT Stihl's or a warranty problem, because it is a too much oil issue. If it was ran on too much oil mix, Stihl is not going to pay to clean up the mess.
All I'm saying, in my experience this is usually user error on oil mix and not a mechanical warranty problem, and is simple and just pocket change to test before taking it out-of-service and spending more time and money going to the dealer to drop it off and then to return again to get it.
If after testing fresh verified fuel mix and it is still pissing out oil, then it is a Stihl warranty problem.