At the moment the stacking order is as it is normal with HTML: following elements are on top of the elements before. So when using x-offset for an element, only elements that are an the right side of an other element or in the next row can be on top of other elements.
It would be great, if the stacking order could be changed (for example in the context menu). I already tried setting a z-index on elements but this doesn't help since the rows have their own stacking context (I think). So maybe it's a bit tricky.
But another way to do this would be swapping elements by using x-offset. So you put the element you want to be on top to the right, the other one to the left, and then change their position in the grid by setting an according x-offset. This does not work at the moment due to the bug report I filed concerning vw and percentage units for the offset. So maybe this puts a higher priority on the bug report.
Thanks for listening to everything posted!