I agree with everyone on the royal icing (or if you don’t want to make a whole batch of RI just for dragee-sticking, I would also suggest piping gel). I just did a cake a few weeks ago with a good amount of dragees at the base and top of the cake and I started by using sugar glue, then when I realized what it was doing to the dragees, I switched to royal icing. I also noticed that it seemed like the dragees attached with sugar glue never really seemed to dry onto the side of the cake… they just stayed wet :(
Baker from The Epicurean Delight - Falls, PA