So here's what I think we've more or less got, with some fluff explanation.

-Superluminal travel is 'Edge to edge' and doesn't work inside the gravity wells of stars.

-Superluminal travel is normally only possible along star lanes, though extremely powerful Vacare may be able to see into and navigate along the void itself.  This is dangerous and possible only for smaller ships capable of quickly reacting to fluctuations in the fabric of the void. 

-Travel along the star lanes either requires a Vacare navigator or a Cognition Engine, generally speaking Cognition Engines are very costly and do the job of an AI without the capacity of originality or introspective thought.

-AI Navigators were common before the Machine Wars.

Correct me if I got anything wrong there?  Now my assumption for how machines can navigate starlanes is that they can use a sort of advanced predictive math to plot a course along a fluctuating star lane.  Vacare would be able to see the fluctuations in the void directly and peer ever so slightly into the future to follow them.  Now the most powerful Vacare would be able to see the very fabric of the void and follow rapidly changing currents to get where they want, but the ship would have to be nimble enough to match the course the Vacare plots.  Even then, it's an exceedingly dangerous game to bypass hyperlane.


Anyone want to add to or dispute that?