Epic Wheloon Prison wilderness area. The quests are lvl 26 on Normal, so maximum level range to run without penalty is 30. The wilderness area is maximum 29. If a 30 is in the group, you get no XP for slayers, explorers, rares. So one small thing I'd like to see is the wilderness level range increased to 30.
What is your one small that can be quickly and easily implemented? This isn't an opportunity to ask for nebulous system changes or rolling back to the classic AC model.
One small thing. Something that is a discrete, small development tweak that would help nudge things in a good direction.