A year or two later, a parent complained and said that it was embarrassing to her child that the chart was public knowledge and wanted the charts removed. I took the charts down and put students' names on separate Excel sheets in a 3-ring binder so each kid could see on their own chart and no other ones. Not as good but they still liked the stickers.
If I were you, I'd go with the charts on the wall and wait for someone to complain.
BTW, your local teacher store has poster board size Excel spread sheet things.