That 90 minute to do a full ng+ run number is kinda nuts but an interesting design choice. I ended up not picking up starfield but I do hope someone takes this novel ng+ approach and expands on it to create a game more focused on that as a story telling tool.
Heck, THIS is what studios should be using AI for - write a solid base story and let the AI build on that to create a more truly infinite and distinct set of new loop possibilities. (I would say your first 5 or so runs should be handcrafted, tell an interesting cohesive story, and then if players still want more the AI can kick in and offer additional replayability)