It seems to me that all the ideas for improving the humble derigable assayed within this august portal focus too much on the machine itself and ignore the milieu of its operation.
The inescapable fact remains that the lift engendered by filling a large container with 'lighter than air' gas is dependant
on the quantity of the surrounding atmosphere displaced theron.
Much more lift could be generated from a fixed quantity of such gas if the surrounding atmosphere was encouraged to become denser.
I propose a project of such a scale that the familiar moniker of 'Manhattan' could credibly be attached without hyperbole.
This monumental effort would require the construction of hundreds of thousands, nay millions, of carbon dioxide generating machines. These would burn a petroleum distilate to produce this gas, which is denser than the current composition of our atmosphere.
Over the years the density of the atmosphere would increase thus improving the performance of our lighter than air ships.
The waste heat produced as a by product of this process could be used to generate electricity or power some kind of automatic mobility device.
I am sure you'll agree this is as sane a proposition as many documented on this site.