I know that this has been mentioned and suggested a few hundred times already, but I was thinking that I needed some puzzle practice in game (still suck at 3x3's).
It would be nice if there was a solo quest located somewhere in the game that was structured similarly to the kobald dog quest. All that is required is to complete 3 puzzles, a 3x3, 4x4, and a 5x5. These puzzles unlock little trinkets that are required to collect to complete the quest (think reclaiming the storm reaver fresco art pieces here) and pay little exp. This would either provide practice at solving the puzzles or get players accustomed to the wonderful puzzle solvers available without a time constraint involved.
This would give an option for those that want to practice the puzzles to do so, but not leave anyone out of a high exp quests due to hating puzzles.
This same approach can be used to incorporate different puzzles that are required in raids, but not easy to practice. (GH raid comes to mind here)