I made
an attempt at one way back when based on an obsession with the Progenitors, though I'm pretty happy with the potential in hybrid affinities.
I went through your idea. I love the idea here, and obviously it would require a re-work of the science victory. I think that they could change the science victory to something far more interesting, such as creating a type of wonder that is a major step in human technological progress( Ex: a wonder that can shape the universe to your will), Research the ability to travel between universes, and gather people and resources to establish yourself there, or even sending a ship into a black hole to discover it's secrets.
I am having a hard time coming up with more science victories that are not similar to Civ V's space/science victory, and that feel glorious enough.
Back to the topic, I love the idea of the progenitor obsession. I personally think that all of these affinities have a physical change (or lack thereof (purity)) in people, and a clear goal for where humanity is heading. Yours has a clear goal, and for the physical look.
Now as you said "Purple and white are the general color scheme, and Discovery has an almost mystic look to it.
Taking some notes from the Protoss architecture design, buildings in cities appear elegantly decorated: somewhat like technologically advanced temples.
Similarly, faction leaders adopting Discovery gradually move towards elegant robes, strange devices on their head, and potentially glowing eyes.
Aesthetic references to the Ethereals of Xcom are extremely welcome.
Units would appear strange and delicate, with large parts that look like generators of some kind and lighter armor."
Don't you think that these people would be inspired more by the only source of progenitor proof that they have? The very circular ruins, made of stone. That being said, if they are enlightening themselves with visions, I think their clothing and architecture could very likely look nothing like the progenitor ruins themselves.
I love the idea, thanks for posting it here.