I'm literally still on the topic of proxies, but it's ok, you won't word salad your way out of this.
I have done my research, I've detailed how it works in previous posts if you want to do yours.
Really man, you are talking about postmen and street cleaners.
You went from
"The description of proxy meshes is incorrect here, it's all the original mesh, just collapsing the mesh into less complex representations while aligning the edges to adjacent representations in the same node depth."
to
"There is no tessellation when using Nanite, they literally swap out the triangles to render with more detailed meshes, not divide existing ones."
You get tessellation wrong and then ignore it and then say later.
"Nanite is an optimisation around selecting the correct data to sample, swapping things out behind the scenes, but there is no "Simpler Version"
with
"The data structure is virtual, therefore it doesn't need to store all of it's data in RAM, but the structure contains "All of the data", even if it is streaming parts of it"
You are conflating everything here showing no understanding the subject matter, Less word salad, more word soup. A less complex or "Simpler version" is not the same as the source mesh.
To virtualise something you, by definition, represent it in a lighter, better, simpler representation of it be that a VM server, Proxy Host, data set, Models. I never said the data was not present, in fact I say the exact opposite in the video and posts, this is my point you are trying to shift the conversation which was and I quote you.
"The description of proxy meshes is incorrect here, it's all the original mesh, just collapsing the mesh into less complex representations while aligning the edges to adjacent representations in the same node depth."
And then you confirm you agree as above by saying in the render stage it represents the source model with a less complex version by tessellating ( which you described but did not understand ) on the fly. I.e a virtualised representation as needed per scene, aka a Proxy model.