Yes, fuel used last lap is always the reference.
Currently for E-Challenge, you can only rely on the actual fuel number and be quick with maths.
I’d say fuel is also really important on ICE cars, if you race to a fuel number for an endurance race, it’s one of the most important things.
Problem is really the F12 menu being a bit big to have open for a long time as it can block most of the right side of the screen.
On the fuel topic, would it be a big workaround to “fuel to x%” instead of “add fuel”?