Personally I found the ability to spot illegally moored airships at night or to tell when the streamers suspended beneath a tethered kite were of incorrect dimension to be jolly useful when instructing at PPL level..........NOT!!
Apologies for the confusion with the poll - I meant 'FIs who hold no higher licence than the NPPL' in my options. I.e.- NPPL plus appropriate hours plus some form of NPPL-level FI course.