User blog comment:Brandon Rhea/New Page and Article Headers: Official Release Date/@comment-26402117-20170527142419

It's a good start. I would be after two things:
 * Allowing cascading customisations to affect the header too, to prevent clashing.
 * Also offer more customisation to the header down the line, through the Theme Designer if CSS and JS are not on the table. Maybe being able to make the image more translucent, and being able to make the header image wider.