I'm not sure what the significance of 10,000' is, given that one may be over the ocean on one portion of a leg, and over high terrain exceeding 18,000' on another. Look at the evolving terrain beneath the aircraft and make decisions...not just a line at 10,000' (which becomes irrelevant if higher terrain is below).
If you are stumbling along, and experience a depressurization, then you swing into the emergency descent - which as a standard stops at FL100. It would be all too easy to do this over the Alps - with a nasty TERRAIN alert and subsequent problems. Hence the brief that, once over terrain with a LSALT above 10,000 we need to be aware that we shall do something different.
Enroute, navigation is a primary concern, of course,
Not these days, with dual GPS enabled P-RNAV capable FMCs.