Not sure if they'd do this.
They have the fuel on the clipboard to help out with mission planning, but I don't think they want to take too much away from actually looking at your fuel gauges in your plane. You could time this out on a mission sometime and get a good estimate at what each tank burns without WEP. I just try and keep checking my instruments when I'm burning specific tanks first. I wouldn't be opposed to it if it were added, this is just my thought on why it might not be there in the first place.