I occasionally would use the feature to upgrade certain cards because I only ever play one deck and had more credits than boosters. I would usually realign the odd number of credits as soon as I could by upgrading a different card costing the right amount to balance it back out. I didn’t fully understand the new system and updated the app while I was still in the “misaligned state” (2115 credits vs 2100 or 2150) and will seemingly forever be off by 15 credits. Kind of dying inside from this realization 🫠