Update from October 22, 2020
Many content types now have a default margin-bottom and margin-bottom options.
When a content type is placed within the Advanced Grid Wrapper (AGW), their default margin-bottom is cleared to zero. All Content Types have 34px space between each item within the AGW (except Accordion Stackable). The AGW itself does have margin bottom options.
Note: Accordion stackable are an exception to the spacing within the AGW, they retain their margin-bottom: 20px (see accordion stackable for other design instructions).