Aha, so it would be better to remove the margin from those headings and depend on the vertical gap option to handle the gaps.
In essence maybe, but it might only apply to last block in each grid-item (column), since margin is also used for the spacing between elements inside of a grid-item like in this use-case:

As for mobile then it is messy when you see it like this, but there might be use-case where you want it to space apart, even on mobile, like images with box-shadows for example, or images that cross element boundaries by way of floating or positioning.

What I actually found missing right now, trying to correct my mistake, is a ‘reset’ option for margins for example.