I am entirely familiar with MDR, thank you very much - I fail to see the need for your evident hostility.
The service pilot to whom I referred hadn't flown a slow aeroplane for about 2 years - but had no idea how to use a navigation computer nor how to use MDR to obtain a groundspeed. He just used 1.5 mile per minute groundspeed and guesstimated the headings using 'clock' proportions of max drift. Sorry - I don't think that's good enough. There's plenty of time to do a proper pre-flight navigation plan for a simple triangular navex; in-flight errors should then be relatively small if the plan has been flown correctly. During the diversion element of a PPL Skill Test, the applicant indeed uses MDR after first measuring track and distance....but are taught how to do that properly.
This is basic stuff - all PPL students are capable of it, but why isn't the military bothering anymore? I recall many sessions in a classroom at my UAS, RAFC Cranwell and even at Valley using the Dalton - we had the time then to bother, it seems....