Could this topic end up with those who fly the machines and have a vested interest in their own survival and the regulatory body who has other thoughts, at loggerheads with each other, as usual!
The only thing a fuel gauge tells you is that one is fitted. That was the advice of my instructor and it still holds true today.
Do instructors nowadays pass on these words of wisdom or are they so computer orientated that they believe what they see without question. Oh what a degradation of standards!
As equipment gets more reliable the standards of survivable thoughts deterioates. IMHO