i generally do 2915 - the level 49 comic con meteor. I head into the middle, avoiding releasing the "helper" who actually is more of a griefer for afk'ing, pull lore pets, click hybrid and tab out (auto-burn, of course). Generally if i come back in 10-15 the map is either clear or has one mob left trying to walk through the rocks somewhere, occasionally there'll be two. So it only works well as afk for doing other things while you're around to restart. Great for house chores or playing other games or watching something but not a start and forget like you're wanting. I've tried various versions of the cave map but i find that many of the mobs don't get around to you or get behind you when you move up. As far as something you could leave going all day, doubt there are any options, as AE was specifically set up on live to avoid that sort of thing.