I want this, but it might be harder on server math if you wanted to go quite far. The optimization of picking the optimal jump distance, then finding a path that fits it would be a large number of iterations to find the 100% best path. Also if you got to your destination with literally 0 fuel left, that would be bad too. Its just too complicated for a perfect solution that makes everyone happy.
Instead I offer the following idea, set the fuel limit yourself.
I do this all the time by using cargo capacity to reduce max distance, which fakes the system into using a slightly shorter jump, but at like half the fuel cost. However only works if you equip cargo racks and if those racks are empty. And even with all that, the slider range may not do much.
So just give us a 'max fuel' slider with increments of .1 tons and show us the new jump range based on that fuel.
Using Coriolis real quick by telling the site I have less than 8 tons I get the following jump distances: (Using a max jump spec'd Anaconda, so the highest numbers are very good)
8.0tons = 65ly (100% efficiency)
6.1 = 60 (121%)
3.7 = 50 (166%)
2.1 = 40 (234%)
1.0 = 30 (369%)
0.3 = 20 (821%)
0.1 = about 13 (1,231%)
There is no point being economical jumping 5ly at a time when .1 tons gets you 13, lol,
But doing a 40ly jump uses 25% of the fuel to get about 60% of the way there.
and 30ly is 13% of the fuel for 46% of the distance.
(EDIT, just threw the math into excel real quick to get % effeciency over a max fuel jump. Just by reducing the max range by 5 lys you get 20% more efficient, which means 20% more maximum range on one tank of fuel)