I do have the answer on whether an in-state package goes through a national hub (Indy or Memphis for FedEx) when shipping in-state. The answer is...
Sometimes.
From a major city (Denver metro) shipping to another Colorado town, it stays in state. From a smaller city (Grand Junction, Colorado Springs) it usually goes to Memphis.
Typically. There are other variables in play that can affect routing. What you DON'T have is absolute certainty that ANY particular package will stay in state during transport. Denver to Denver (Dallas to Dallas, Miami to Miami, Peoria to Peoria) SHOULD stay in state, but may not.
Sorry that I cannot bring ideal news : )