This is getting incredibly interesting. I’d love to know what ML1 is like physically, mentally, emotionally… any -ally really. (See what I did there?) I wonder if they can possibly be prepared for what they find outside the Milky Way, if they find anything at all.

I agree with the comment above. Each bit leaves me wanting to read more.

Very intelligent setting. Shows a lot of imagination, reason, and thought.

One sentence’s wording confused me a bit, though:

“He had learned what he could, and built a cultural memory that would last, that peace would endure.”

The wording is a bit unclear and confusing. You might consider breaking this up into two separate thoughts.