Engine Burning Oil problems of the 2014 Subaru Crosstrek

I have experienced rough idling with my 2014 Crosstrek limited for about a year. During this time my check oil light has come on twice. I brought my car into the dealership in fayetteville, ar where they began the oil consumption test process. Thus far the dealership has flushed my coolant and oil and replacing o-rings and valves, replaced more o-rings and my ac compressor, and completed four oil consumption tests each time I drove 1,200 miles and consumed 8oz oil (10. 1oz is considered failing). My car continues to rough idle to the point that I cannot let it idle inside the garage without shaking the walls inside the house. The rough idle happens all the time, when I first start the car, after I have driven for a while, and during routine trips around town, anytime the car is idling. The dealership has advised me that rough idle and oil consumption is normal with Crosstreks and nothing shows on the computer scanner. They refuse to do a mechanical check to further diagnose the issue.

Excessive oil consumption. Oil lights comes on every 1000 miles.