I just noticed that on my two Touchpads the amount of overlap of stacked cards differs (by the same amount in portrait and landscape mode, btw). I noticed it because when I stack a second card on top of a calender (in week view), then with one of the Touchpads I'm able to still see the colored events of the left column while on the second Touchpad I'm not able to see that colored column at all when stacked behind another card.

Therefore my question: It looks like the offset for stacking cards can be configured somewhere, but I have no clue where. Perhaps somebody could give me any hint where to look?