I will need to create a whole meta tag constructor for this, with all features like changing order, adding, deleting, it is a big piece of work and there is one crutial problem:
It looks that seo specialists like to add some very specific meta tags, how could I guess what they need?
For example, by googling there is info than meta tag could have the next attributes: name, content, scheme, http-equiv.
It does not say about charset attribute, in which case it is a single meta tag's attribute.
And after looking at web sites I very soon found meta tag like:
<meta property="fb:app_id" content="966242223397117" />
So It looks a bit comlicated to create constructor for all cases