Starfield Tiles are Connected 100%

In this video, using a StarfieldCustom.ini file, I was able to move from one tile to another, while showing New Atlantis being loaded on the fight...Meaning that the barriers in the game currently is artificial and not actually an Engine limitation.

StarfieldCustom.ini
[General]
uMaximumPlayableAreaWorldCoord=614400
fPlayableAreaX=1000.0
fPlayableAreaY=1000.0
fPlayableAreaZ=150.0
bBorderRegionsEnabled=0

Point of Note

If you look at the quest icon, you will see that it changes from a ship to a blue dot. That is significant.
When you have a quest in a different tile on a planet or on a different planet, and you are in a different cell from your ship, your quest icon will the ship
When you have quest on a different tile on the same planet or a different planet, your icon will a blue
So when my quest icon went from ship to dot, you can clearly see that I was in a different tile/cell.

Another Point of Note

In the current game, the only time you get the ship quest icon is when you in a major city like Neon and have a quest on a different tile...However, in the June Direct, the ship quest icon was shown in the over world, many times, like it is shown in my video...Take that for what you will.