Hi,
Due to all the mobs that have a larger spawn time being heavily farmed for cards, I would like to suggest a method to complete/obtain the quests for/from elites. to have mini version of the mob or a totem/chest that players can interact with to get the necessary progress with quests. these mobs/items shouldn't have any other loot apart from the items needed to progress in quests and should have a fairly quick spawn time.
a few mobs come to mind
Giant guardian in Silverspring, I got the quest to use the sheepskin parchment near it at around level 15-20 and had 4 level 105 classes before I managed to complete it.
Ayula in Dust Devil Canyon, drops an item to start a quest, one of the few remaining quests I have on my main
Sharleedah access to Hodl.
I am sure there are more but I cant think of them at the moment
this would take away the frustration of not being able to progress in the game, while not taking away the fun of actually finding/killing the mob and obtaining its card.