As I'm usually the loudest in favor of the seven day rule I feel like I should say - this is fine with me.
Thank you. We appreciate your feedback in particular on these things as you definitely understand the math and details of the game far more than most people and your comments and criticisms are usually spot-on.
Regarding the single potion charges - the average expected DEC value of an Untamed edition card (which is what we are using for rewards going forward) is approximately 60 DEC. Legendary potion charges are 40 DEC and Alchemy are 50 DEC, so on average 1 of those potion charges is worth 15 DEC less than a card. That discrepancy is currently made up by the 1% chance of getting an Essence Orb.
so I did the exact maths on this and the EV goes down from 93,61 DEC per reward card to 91,33 DEC per reward card.. doesn't seem like much but it actually is...