Thanks for that one FlightDetent..
As a Grd. Eng. it's a bit of a nuisance for us having Nav Lts "As Req'd" , because that means that some flight deck crews switch them off and some guys leave 'em on . Neither of which is wrong according to the C/L.
But as an earlier contributor remarked , they're best left on all the time except for during prolonged maint. periods.
Having the F/D crews switch them off and then switched on again is the best way to pop a filament and they will be switched on again anyway by Engineers as it's part of the Daily Check.
As far as I'm concerned , leaving nav. lights on the same system continuously is best by far. Then if one is spotted as inop at a base-stn , it can be re-lamped , or if down route , it can be MEL'd .
I don't wish to delve too far into SOP's or their politics , although one does sometimes wonder if they're the product of knowledge and experience , or concocted by self-important little career monkeys.