A: First off, the main purpose of this tool isn’t SEO. It’s a lead magnet. Having said that A) You can add meta data and enhance SEO. It works. B) using CNAME, if done right, absolutely can be part of your SEO strategy since you can link content to your other pages. To answer your question specifically, no you cannot add Subpage as an extension to the root domain. Many users see excellent SEO results