For quantum Locket, and potential future "select element" cards, PLEASE change the current format.
Current: select any card on play or in your hand and pick that element
My idea: select the element from your quanta pool
Why is that? Because you may want to select an element that's not of any card on the board. The basic example is to activate off-element abilities of creatures and permanents, like Parasire, Tesserract, Clepsydra or Unstable Gas. The other example is to fuel a card that you are expecting to draw and didn't draw yet, of one-offs like combo cards in a OTK where you aim to have the exact quanta you need and no more.
Please. Support a good quanta selection method.