You can take ALL settlements, and do strictly settlement related quests to get them or unlock settlement stuff. I was thinking of a few ideas that I'll list here, they are just spitballing and likely won't all work together, just random thoughts, but I'm hoping to get the ball rolling. I just watched most of MATN's go of it and it was entertaining as he always is, but I found myself asking what would be needed to do a full playthrough like this? Because after you grind levels and build everything then what? So I was hoping some of you that have tried it or something like it could share your thoughts.
It seems like it might be fun but it wouldn't be entertaining for more than an afternoon of playing. I've seen this challenge posted about and watched some YouTube videos of it.