Experimentation
Replace, insert, append, before and after
Five ways to place HTML relative to an element you selected, which is enough for almost every structural change.
Editing an element covers most of a variant, but some changes are structural: a banner that has to exist, a trust row that belongs under the buy button, a block that needs to be gone. The HTML code editor handles those, and it does it with five placement actions against whichever element you selected.
Replace swaps the element for what you wrote. Insert puts your markup inside it at the start, and append puts it inside at the end. Before and after place it as a sibling, immediately above or below.
Choosing a placement rather than writing a DOM script is what keeps the change readable later. The implementation hand-off can state where the markup goes in one line, and the collision model can tell that two variants are competing for the same element.
These are ordinary changes on the variant, so they combine with everything else: an appended block can then be styled in the properties panel like any other element.