Wonder Pick Refresh Button
To me it feels like nothing of 4 or more stamina will appear if i have all 5 stamina charged, I have to spend it so the system shows me something I want that will cost me Wonder Hourglass or gold, so it feels like the system is trying to milk me.
So I figured that if I want to see something relevant, like a full art trainer or a 2 star mon, i need to keep my stamina low and to do that, once a I have almost every card in the set, I have to take something i dont need just to spend the stamina.
My suggestion is, you could add a refresh button for all wonder picks, so instead of wasting it in some wonder pick I don want, I could spend my stamina refreshing the board.
U get the point, I spend my stamina refreshing, so if something good appears it will cost wonder hourglass or gold, increasing your profit.