Board Thread:General Discussion/@comment-32616717-20180421171154/@comment-32271305-20180421174547

The Hidden Potential only works on cards that are at least URs, and you can only Reverse TURs and LRs. If you reverse a TUR to its previous form, it will still be Z-Awakened to UR, therefore the Hidden Potential will be visible.

And yes, not Dokkan Awakening cards just to save Hourglasses doesn't seem like a wise choice to me. As you said, that could take forever. I think it's much better to Dokkan your best cards, and just use Hourglasses whenever you pull one or more dupes. Farming gems to get Elder Kais (or Hourglasses for that mattter) seems like a very good idea, especially now that the Rank EXP has been tripled during this Celebration!