I’ll do my best to have an update out on Monday that’ll add a page level setting to overlap the header and let you choose either dark or light menu text, based on the image you’ll be overlapping onto. Would that help?
Download the ZIP.
Switch to any other theme.
Install the ZIP from Themes > Add New > Upload Theme.
A new page setting will be added on the right when editing any page called Overlap. Ideally, you’d have a full width stretched row in Page Builder by SiteOrigin or similar just below the header with the header margin and page title disabled.