For those who don't know, the Rod of Harmony is an item in Terraria that serves as an upgrade to the Rod of Discord, an item that lets you teleport to the mouse cursor. Overuse of this item will damage the player, whereas the Rod of Harmony lets you use it as much as you want. The catch is that you can only get the Rod of Harmony after you've beaten the final boss of Terraria, which keeps it from destroying the game's balance.
The recent thread about an endgame Walking Cane got me thinking: how would a Rod of Harmony-esque upgrade to the Lazy Explorer work, and would it even be that good? The basis for this thought experiment is that 1) the upgrade would require both Charged Spark Arcs and Dark Tatters, and 2) it would functionally be a Lazy Explorer with infinite durability and no sanity loss on teleport.
Sure, on paper, infinite teleportation sounds crazy, but if it was locked behind Charged Spark Arcs and Dark Tatters, you'd only gain access to it by the time where most of the game's progression based content has been cleared at least once. Other than travelling across the map at record speeds, I don't see many uses for this item.
I guess you could bring it to Fuelweaver? But by that point you'd already have access to at least one Shadow Thurible, so it's usefulness there isn't as high as one might assume it would be. If you wanted to teleport i-frame with it, it doesn't seem nearly as good or convenient as Wanda or Wortox's teleport i-frames. Having to swap to the item before you can teleport would likely make it much clunkier to use than just kiting. There's also the chance whatever you're fighting de-aggros randomly, further interrupting the flow of the combat.
Honestly I think the main reason something like this won't ever be added isn't that it'd be too strong, but because it'd basically defeat the point of playing Wortox lategame, and Wanda and Winona would be marginally less appealing due to everyone else having access to super fast map travel.