Any efforts noted for a south to north transect of GSMNP from mingus creek trailhead to the summit of Clingmans Dome down to Elkmont trailhead. This route is detailed in Treking in Southern Appalachians.
It looks to be 41.3 miles with 10,300 feet elevation gain. It looks like an instant classic. Billy Simpson and I are planning a possible trip in a few weeks. I like the idea of going from south to north and going from 2,000 ft to 6,500 ft.
There have been similar runs, but that route in particular I don't think has been run for time. The only record associated with a north/south traverse that I know of would be Gerry Eddlemons' run from Gatlinburg to Deep Creek in the early eighties, his time was in the low seven hour range I believe.