>>>>>I am assuming from what you said that these have no affect on the document itself as it's imported, exported, or saved

Correct

>>>>it's confusing as to why the default settings for AutoCAD would be set so that curves were jagged.

The curves are jagging only on screen, in fact they are curves. The settings for curves smoothing saved inside DWG file, but not globally in AutoCAD. So what you see on screen after opening DXF (DWG) exported from AI is AI job.

Once again - please, share your AI and DXF files here, we can look at them and will try to help you.