Where is the difference?
Ground isn't included within the op-amps linear I/O range (for unused input configuration) because the documents specifically state this and also describe the degrading effects if it is.
I've spent many years developing and working with measurement systems and LabVIEW (G). Didn't get working with Arduino (C, C++) until much later, but I've always watched for what seem to be subtle wording differences pertaining to ranges and limits. Note that LabVIEW has this covered simply by clicking on the lower or upper limit (or both) diamond(s) for inclusion.
Anyways, the unused op-amps configured as a buffer should have its "+" terminal configured at mid range voltage (ideally 2.5V) when using a 5V single supply. Otherwise, you're just amplifying ground noise and disturbances and spreading this throughout the chip. Note - for split-rail supply GND is OK as its already mid-range.
