Metatag, Metatag plugin; having a meta tag plugins content (per object) should remove the admin meta tag content (global)

• Feature request

You can use the plugin meta tag (https://doc.tiki.org/PluginMetaTag) to set a content for a meta tag on a Tiki object.
However this will be added as a new metatag in the head keeping any other value you may have set (admin, control panel same meta tag or automatic feature).

For exemple:

1. I have at tiki-admin.php?page=metatags in the field description : "My very general description".
2. In a wiki page about Tiki and I would like to have specific description for this page.

I set the following plugin

{metatag name="description" content="Tiki is the best"}

After saving, if I check the page head the description "My very general description" is still there and I can see a second metatag for description with "Tiki is the best".

Results of having meta tag duplication (twice description meta tag) are unclear.
From page validation point of view it seems to be forbidden and bad.
From SEO (Google) point of view it is unclear if the second tag will ignored, will replace the first one or will be considered as an extension of the first one. This because it seems it depends of the meta tag (robot = extension, keywords = not used anymore, description = unsure ?, etc).

Each meta tag nature is different and Google may change its rules at any time.

So, to use the plugin meta tag, it should be advised to remove the "global" values for a meta tag which leave ALL the pages (object) without this meta tag.
Thus I have now to set the meta tag plugin on every pages (or objects). ?

It would make much better sense in real life to have the "admin" meta tags used by default and have the "plugin" meta tags used if they exist.

Also, as side effect it forbid from using the multi-lingual admin feature for meta tags (you can't use any)

Adding a condition to select the value to be used;
If a Plugin metatag exist (for the url) and a meta tag content is set = use it, else use the admin global meta tag (default).

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org

This bug has been demonstrated on show.tikiwiki.org

Please demonstrate your bug on show.tikiwiki.org