My truck and experience...
Seems that on the hot days when you need it and are thinking about it, it meets spec, but at the very top end of the spec. 55-56* driver's side center vent temp.
However, take it in on a 60* morning and have them do the test, at full operating temp. It will no longer meet spec, as the lowest vent temperature received on the driver's side center vent will be right around 52-53*, while the spec calls for a 45* max....
Kinda counter intuitive, but points to a significant issue in the hvac blending box. Now clamp the heater hose off, and you will get low 40*s after about 10 minutes of running and it removing the residual heat from the heater core.