"Best experience possible" might not include the climb out of NOC...
Hmmm.
Your analysis of the Smokies is spot on; also, there are no really good bail-out points along the AT through the Smokies -- some side trails, but no road crossings other than 441.
How about leaving a car at Winding Stair, and getting a shuttle Dick's Creek Gap in Georgia? That's almost exactly 40 miles, and includes Standing Indian, Albert Mountain, etc. Nice section. You could hike to Plumorchard Gap four miles in on day one. Should be a reasonable hike for three full days and two driving/hiking days.