Most of the commercial bullets use high temp lube to keep it on the bullets during shipping and storage due to high temps. (My brother lives in LasVegas and "likes" the high temp lubes) . However, I've seen him miss "easy shots" because his bullet lube fails in low temps (i.e.:hunting season). This lube is often intact on a fired bullet, meaning it failed to do it's job. Couple that with an undersized bullet, and over hard bullet means LEADING!!! If it requires a heated sizer/lubricator, it might fail in low temps! I.e.: shot of a lifetime on a trophy animal. I prefer SPG. Flows through my lubricant-sizer in basement in winter... It ALWAYS works.
Coating the commercial bullets with Lee liquid Alox, or even stripping factory lube and re-lubing is a trick I learned as a high level PPC Competitor. I stripped Star, or Precision Delta bullets and relubbed them with a "known" lube for superior performance. Better the "devil you know" than the one you don't! Just one less variable.
Now, we've got powder coating too!!!