Very cool. You've certainly helped hundreds of hikers then. Thank you! Elizabeth Etnier also has a free spreadsheet with the mileages available here: http://smokymountainshiking.com/ She also has an interesting spreadsheet ranking all the trails by Energy Mile Theory. As for accuracy, there seems to be less than a 1% discrepancy between the spreadsheets, which seems acceptable. It would certainly be advantageous to beat a preexisting record by a wider margin if at all possible.
Update on Jeff:
Elapsed time*: 8d, 11h, 3m Staged time: 2d, 20h, 53m Total miles**: 266.38 New miles***: 224 Projected total miles: 947.4 Projected total days: 32 Projected days (staged): 10.2 *assumes same start time each day, based off Jeff's Strava **uses Jeff's GPS data, shown to err on shorter than actual mileage ***estimated from quick nightly tally of $1 park map mileage, unofficial