Adding custom meta tags in "Manage MetaTags and Keywords" area

I have a client that has an SEO company doing SEO for their website and they use the meta tags so they can just ctrl-click to add meta tags to the page. TVs aren’t really even something they want to do, and it would be nice if I could just add custom meta tags to the list that is there. It DOES say that the list is not complete.

MetaTag management will likely be removed in a future MODx version because TVs are a much more appropriate way to handle this need. Using TVs with @INHERIT is an infinitely more productive way to manage page specific descriptions and other relevant meta-content. For the rest that don’t change all that much for the site, they belong in the Templates themselves.