Silent Cals second suggestion also appeals to me:
Little Haystack, Mt. Hight, Guyot, Franklin, and Clay while not 4000 footers could be added after everything is filled.
Maybe people can sign up for these peaks and, hopefully, agree to switch to one of the 48 if it should suddenly be uncovered.
Of course, the more people that cover each peak – the more there is built in back up if one person gets sick or is otherwise unable to hike.