I can't help but keep wondering if "map shift" is a problem invented by someone who relied too much on following the magenta line without crosschecking other instruments...
In a "steam gauge" airplane with IRS but no FMS or Nav Display, "map shift" happens every time an update is made or lost, and the autopilot and/or flight director move the airplane half a mile left or right to match the latest solution. We all get used to the phenomenon, but also crosscheck the HSI and/or RMI when VOR or ILS is available. If you religiously crosscheck your Nav Display with raw VOR data, "map shift" should never catch you by surprise.
