On a related issue: does the check-in time of a pax affect the upgrade probability or chances in oversold situations in any way at CO?
(I apologize for jumping in)
When looking for victims to IDB (Involuntarily Deny Boarding), they often go for whomever checked in last. On a flight last year I heard an elite (who was going to be IDBd but who was saved by a benevolent fellow passenger) express surprise that his status hadn't protected him.