While tuning my kids car I noticed the factory settings for the VCT cam retard are quite large at some mid rpm low load map points. Is the factory calibration trying to achieve an Atkinson Cycle here for mpg?

Also, the factory max VCT retard tables don't allow the requested retard to be met at many map positions. I looked at the same tables in a factory Shelby tune and it was much better. Is this just an over site/shoddy tuning in the factory calibration? I have adjusted all of the tables and see VE north of 100% at high RPM, both from absolute load and calculation from MAF, so I feel the engine is breathing pretty good now.