I know I can't change it in flight but imagine... I set my fuel to Huge lets say... half-way through my trip, I decide to
save for later. In the meantime I setup a new scenario and select realistic fuel consumption.
Now when I reload my last scenario where I was in-flight, what's my fuel consumption? Realistic at this point or Huge? I
can't exactly land halfway to Mars to change it back

Is it enough that I change it in DGIII config before loading my old
scenario?