I have no idea if this is even possible, but what about a map where the most important axis is the vertical one? Instead of ships charging across the battlefield from long distances away, the main thing is moving up and down to reach your opponents.
I'm thinking an immense canyon with debris scattered across the bottom. It would still need to be wide enough across for weapons like the Mercury or Lumberjack to still be useful, but it would be taller than it was wide- a tall, thin space rather than a flattened cube.
Vertical positioning is already an important part of the game- no ship can hit an enemy that's directly above or below them, and attacking from above or below has advantages and disadvantages (whether you're gunning for the balloon or hull, for instance). I think it would be fascinating to see the strategies a mainly up-and-down conflict would create.
If anything, it would certainly get more use out of Hydrogen and the chute.