Thanks for this plugin. I was wondering if it would be possible for you to add a couple of hooks to this plugin. So instead of:
$_seodt_platforms = array_merge( $_seodt_themes, $_seodt_plugins );
... you have:
$_seodt_platforms = array_merge( apply_filters('seodt_themes', $_seodt_themes), apply_filters('seodt_plugins', $_seodt_plugins );
That would let other plugins / themes add their meta fields to what you already provide.