(Spoilers!)
Bethesda have integrated the idea of what New Game Plus could be, right into the core storyline of Starfield. In this game when you finish the main storyline, it is, to use an over-used term "just the beginning".
If you choose to travel to another Universe through the Unity, you'll lose your ships, weapons, loot and companions, but you'll gain a great Starborn Ship, a Starborn Space-Suit & Helmet, and the chance to start a new play-through where the other main characters know you are different - and apparently certain quests and missions are different too.
Starfield New Game + doesn't stop there though - each time you pass through Unity there are more changes, but you'll have to seek out other videos if you want details about that!
Thanks, Rob.
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