One, I bought this car used with like 160,000 miles on it, two, 6094M only specifies MRV limits more strict than SAE, nothing else, even cheap SM conventional would've met 6094M, which GM programmed the OLM to go ridiculous lengths on I think it can go upto 10,000mi. I'm using premium brand synthetics, none of them are poor quality oils, Dexos1G2 is mostly to address issues with direct injection and small displacement turbo engines, most of Dexos1G2 is covered by GF-6 now, any synthetic oil far exceeds the factory specified oil and for my application the difference between a full synthetic euro A3/B4 oil or full syn mixed fleet diesel oil and Dexos1 rated oil is pretty nil.Not just for LSPI and timing chains. d1G2 is a strict and stout spec and used to be my go-to oil before my recent experiments.
Maybe you should have cared about using a spec oil for your vehicle. Mine are well over 180k and don't use any measurable oil between 5k OCI's.