About the end of the dust refund period, you should craft Deck of Lunacy then disenchant it, so that you wont open it in future packs if you never had it in the first place.
At 4 mana the card is really bad, and after each expansion, the card will get worse and worse. So you probably wont want to get it from an future pack. To prevent openning one, you can craft it and disenchant it (no undo button) therefore the game will mark the card as obtained and because of the duplicate protection you wont open it.
BUT you probably want to do this at the end of the refund period since if you open it during that time, you can dust it for 1600 dust.
Craftable cards above will be eligible for a full dust refund for 2 weeks after the 20.0.2 patch goes live. Following a hotfix on 4/14, Kargal Battlescar will become eligible for a full dust refund for 2 weeks. In the days following the hotfix, compensation will go out for players who disenchanted Kargal after the 20.0.2 patch notes were published.
Everyone should disenchant Lunacy imo, because it's going to rotate in a year and at 4 mana with the Wild spell pool it's beyond unplayable, people might as well disenchant it now and get more dust, it's not like standard mage needs Lunacy to build good decks.