@ericmock - there’s just been some discussion about creating mesh without going through Model I/O.
I created a project that just builds a cube (but obviously the eight points of a cube could be any number of points) here: Face normal vs vertex normal - #9 by caroline.
We were using color as an example, but that could also be any attribute. The second example (without the submesh) should be the one you want. Just set up the buffers and the vertex structs to match, and you should be fine 
Model I/O is really only to make loading models made in 3d apps easier for us. If you’re not doing that, then it will only add complexity.