Once again, Foxmoth, TOO MUCH HEAD DOWN TIME
????
How much head up time do you need? If it takes more than a fraction of a second to do ANY of the elements I have used then you have a problem - glance down at the bottom of the DI , turn 180, glance at your pre planned drift for last leg - eyes outside, glance at chart to check wind and then eyes outside while your brain thinks about how to apply it then adjust heading, probably 2 seconds total head down time in 60! If you are in the poo it is surprising how hard brain failure can make even simple tasks like turning 180. Radio is great, but sometimes I am non radio - surprising I know, but some of us do occasionally fly aircraft without that sort of advanced equipment!
Drawing the line works the same, should only be done once out of trouble and, if you add in putting some time markers on you line (using your thumb) you might just extend time taken to 3 seconds in 60 for that job!
The time you will end up with a lot of head down time is as soon as you start using any sort of hand held mechanism, and even reprogramming a GPS will probably have more head inside time than this method.
I have used and taught this for many years now with no problem of students keeping their head inside.