Full Support.
Conceptually this is a very good direction for a new skill, and can act as a force multiplier for so many other skills in the game to unlock additional reward space, and new content over multiple years of development.
I think its important to clarify and distinctly define its primary skill training loops, and the form factor that they might take.
Considerations:
• Would the New Exploration areas be hand designed and fixed (needing a lot of new space in order for the act of exploring it to be a viable skill training loop), or would they use procedural generation and generate in a way like an Exploration Dungeoneering style instanced area, or like the Arc's islands?
• Treasure Hunting as a core feature I think is very critical to the skill. Would this involve tracking down the location itself, or include new Clue Puzzle style activities with scaling difficulty, and puzzle enhancements and solving boosts at higher levels? A lot of depth possible there.
• Hidden Locations is also a very good idea, the important point is how could they be hidden well in the current game world? This would need to be a high complexity system of rotating entrance points that could not simply be looked up in a wiki or solved with an Alt1 plugin, the same way that the "Hidden" Clue scroll solution locations are. This would need a very high amount of randomness over a very large search space to maintain their discovery difficulty over time.
• Environmental Puzzles are in a similar situation as hidden locations. They would need to be very high randomness over a large state space to remain challenging over time and be wiki and Alt1 Resistant. Very interesting design space, do you have any specific ideas of what exactly the puzzles could look like or how one might work?