Enabling Page Properties to be used as Structured Data

We have been wanting to enter in structured data to Confluence pages for quite some time. The closest we have found to doing this is the Page_Properties macro which if looked at closely has enabled key_value pairs to be entered in per page.

We would like Atalassian to enhance Page_Properties to behave like page Labels. So when a Page_Property Row is created the first column would search known Labels, allowing autocompletion. When the second column (the value) is entered then autocompletion would occur for that key_value. All keys and their corresponding value sets could then be managed as Labels are currently managed. The Page_Properties_Reporting layer would be enhanced to allow export/import via Excel or restful interfaces.

(Note: in the document attached I've used the term 'Tag' instead of 'Label'