The trouble is, as an instructor I'm supposed to teach all this stuff to my students. What do I tell them...do it this way for the test and my way afterwards
Yes, do exactly that. The PPL as a whole is so full of cr*p (e.g. in the ground school) that if you were to pretend it's really necessary nobody with any intelligence will take you seriously. Don't get me started on the circular slide rule
Teach the official version - the vast majority of PPLs lapse within 2 to 3 years so it does n't really matter!
Actually, the vast majority of PPLs chuck in flying for good within 2-3 years. Only a few remain.
As to what the small remainder "lapse" to, is a good question. Every time I fly I hear dreadful incompetence on the radio. Yet all these people have to go up with an instructor every 2 years. What the **** does this "instructor" do with them??? This is after making all possible allowance for the cr*p radio kit which so many spamcans have.
The best one was the other day, when a pilot, with an otherwise good radio technique, kept using "over" at the end of each transmission. How is this possible? How many decades old could that be? That's done on shortwave (HF) but, in the GA context, only ferry pilots should be exposed to that.