IIRC, the time limit for the dummy expiration is simply the enrage timer of the boss; you can't manually adjust the timer, as in Trixion. I don't believe it's very efficient to enter a duty then leave (especially if you messed up in the beginning of the rotation) every time you want to reset CDs. Asking for an option to reset them with one button is simply a logical and reasonable ask. While I understand Balance is well-respected and many people go to them for game information, I don't think it's fair for their word to be the end all be all of the game. It removes the freedom people have to make their own rotations that they're comfortable with. Training dummies do have their uses but having the option to acquire max resources at the click of a button instead of building them up is another logical and reasonable ask. I don't see any reason they can't implement something like this in the game. They added an "Explorer Mode" to the game so people can just run around... The game is always coming out with content and there's no reason this can't be implemented as well.