While I do find the new card system boring, by far my biggest two issues are the Play bug, which is already being addressed, and seal generation "out of combat".

If you throw a card on a party member who is in combat, that action puts you in combat. However, you do not get a seal because you were not already in combat yourself, which means you need to heal or attack before you can throw any cards. There is also an issue where you don't get seals if you throw a card just before a monster dies. Depending on server ticks, you may or may not get a seal.

My proposed change is just to adjust the seal generation to include if your target initiates combat in the next 3s or was in combat in the last 3s.