I checked for flags and extensions to no avail. According to this post, there seems to be no builtin option at the moment.
You can change the center header by changing the content of the
<title> tag in the HTML source before printing (right click, choose inspect, expand the
<head> tag, right click on the
<title> tag and select "edit text"). The other header values cannot be changed, as the Google employee states in the post you linked in your question:
Currently there isn't a way to edit the header when printing a document. You can currently only turn the header and footer on or off which includes the date, name of the web page, the page URL and how many pages the document you're printing.
An alternative is to save the webpage as a PDF (without any headers or footers), and then manually add the headers and footers. I found this website that let you add headers and footers. Use it at your own risk. You might want to add custom margins when saving the webpage as PDF to avoid the footer and header overlaying with the webpage content. 0.5" as top and bottom margin seems to work. If you want to add headers and footers manually, you can look into the command line tool cpdf.