This is a documented limitation:
"You cannot open more than one card from the same parent window."
So no, I don't think this will be changed in an update. Why would you need to stack cards? Why not just change layouts?
Well, in my app I have a list view, I then click on one of the lines and I want a card to come up, so I can then easily close that window and still be on the list view after. However, the card that comes up may also have something else that I want to access (but keep the original card in the background). When I close the second card, I am still presented with the first card!
I have done this in FM15 by using modal windows, although I really like the ability to dim the screen behind the open card.
Markus, I will check out the Floating card window tutorial.
You can fake a card window with a popover that has a opaque background and covers the entire window. So you could stack one more card by having a card window open, then a fake card popover on top of that.
But yeah I would probably just re think the design.
Yep, I am just re-thinking the whole design. My modal window stacking thing was working fine, so I am just going to stick with that.