Gravity is universal, there is no system or body you can fly to or between where gravity doesn't still have an effect, even the Hutton Orbital the run doesn't allow you to get far enough away from either star to achieve top speed of 2001c. To reach 2001c you essentially have to point towards emptiness and sit there for the better part of half an hour. I believe halfway between the two stars in the way to Hutton Orbital you will reach slowly around 1895c, I am not sure of the exact number, at that point it start decreasing as you have passed the roughly halfway mark and are now flying into a gravity well rather than away from one.
It's interesting in this regard that the game matches as close as possible to reality, the gravity field of every particle in the universe extends to the far side of the universe, in ED as with the real universe there is no gravitational sphere around bodies and stars where gravity suddenly stops affecting ships in SC.
I'm talking about a point or threshold where it tangibly affects your ship to a degree that it slows down enough.
While IRL it might be universal, in the game, we can set a threshold where gravity starts to have a perceivable impact on performance.
That's what I'm getting at. ANd that's what pilots generally want to avoid when attempting to reach a destination at best speed and best time.