How long before my publish date should I upload my book to IngramSpark and set up KDP?

I just came across a social media platform (yes, another one!) called Substack. It seen like it may work well for writers. I even created a profile in there. Is there anyone here with a profile there? Feedback is appreciated. https://substack.com/@itsrogerm

I saw this message on LinkedIn today. This is exactly what @Julie Broad has been hammering for a few months now. Build your authority using your book and your expertise!

Hello friends, I put together a review page to collect feedback from my readers. I'd love to hear what you have to say. Good, bad and ugly. Thanks so much. Please try laptop and mobile versions if possible. https://www.rogermagalhaes.com/book-review/

I ran my book through most (5) of the AI platforms and was really pretty happy with the results. I wrapped it up by asking them to think like a publishing house and give an honest review. Here's what the average score they came up with... Publisher Scorecard Category Score Market Need______________________9.5/10 Author Credibility__________________9/10 Originality_________________________8/10 Commercial Potential______________8.5/10 Organization_______________________8/10 Editing Readiness__________________7.5/10 Institutional Sales Potential_________9/10 Amazon Discoverability_____________7/10 While I certainly wish they were all 10/10, this is my first time writing a book. I now know what to work on...