I'm thinking they will probably stick more on the html side since it is easier for beginners. Remember a header image takes the part as the main preview image. That's why I had to get rid of my main header and add a footer instead. It is a bummer but, that is how steemit works. If steemit changed anything I'd love to see them give us the choice of which image is the preview image. That way we could literally use all we want in the post. Now that would be awesome.