excrab
IMHO in the event of an engine failure/fire en route the flight deck have enough on their minds dealing with the drills without then thinking of drift down levels at or below MSA. Equally in the event of rapid decompression the need to reduce altitude to a point where most pax would not require oxy whilst dealing with the emergency and thinking of terrain is another unwanted problem for the pilots.
As to routing the point I was making was that in order to reduce the risk of driftdown into MSA the flight planned route would take you over the track with the shortest distance to clear the high ground. Now if ATC wanted you to route differently or if wx was on the optimum flight planned route then the flight deck would have to take the risk of exposing themselves and the aircraft to greater risk to comply with ATC or to avoid wx.
That is why I argue that the aircraft is starting to be operated on routes it was not envisaged being used on.