I really like the idea proposed here of <Spacer /> components. I always thought it was weird to assign a margin to elements of a list to achieve spacing. To maintain proper spacing it's often best to either make the top and bottom margins of each element equal, or remove the top/bottom margin from the first/last element. Both techniques come with complications.
Abstracting that out makes it easier to achieve a commonly used layout. Not quite sure the best way to implement this, but I'll definitely be giving the idea a shot.