The suggestion is to add all fuel storage boxes in a secondary, empty variant, similar to how material storage is handled and with their kind of pricing (ergo empty+super cheap).
As an argument for it:
Currently, all fuel tanks spawn in full, which inflate a crafts price. Ignoring container cost, they are 10 fuel per cost, which is very inefficient compared to a good refinery, which can easily reach 20 times that efficiency. I don't think a crafts price should be priced by how much it would cost filled up from a really inefficient refinery. This makes enduring long range crafts extremly expensive, despite them being already less space efficient, considering they have to sacrifice space for a bunch of fuel tanks. Same with supply crafts, which are weirdly expensive. It just doesn't make sense!
The high cost containers also make it even less rewarding to create expensive, but efficient fuel refineries. Ships already loot most of their fuel in battle, so it would be nice if we could at least spawn them with empty tanks and use the refineries to fill them up at launch.