Just to follow up on this, I personally think the solution I propose would work very well and create very reasonable game maps. The only down side I can think of is that existing games saved out as TWA files that are rebanged would result in a different game map than they originally did. You wouldn't be able to duplicate an older game map with the latest version. All the settings would be the same, but the warp structure would be different even if you had the same bang seed. Is that a problem? If it's not a big problem, it's probably better to go ahead and guarantee warp paths are valid between all sector pairs in a game.