I just wanted to say that using the meta fields in the document type form to set the macros for those meta tags is a great idea that I hadn't thought of.

I've been suggesting on UserVoice and even talked with the CTO of Kentico about (Martin) how Meta tag inheritance was rarely suitable for my needs. I had suggested that a new tab or something be added to the document type editor to set those macros. As a temporary solution, I have been using macro conditions based on the document type in the parent document or adding a static text web parts with the macros for the meta tags in them. I like your idea better though, and I will likely start using it.

Your solution also gave me an idea of how the folks at Kentico might be able to easily implement a way to do this without changing too much of the code.

1. Add a tab (or some other place for a form) to the document management field where we can manage the text or macros for the meta tags

2. Upon save, get all of the documents of that type where the meta field values are equal to the values in the form before it was changed and only update those. That way it can keep any values that may have been customized manually.

3. Add an option to the form to replace the values on all documents of that type using a path expression. That way we could overwrite any custom values if we need to, but we can also have some control to leave some of them alone.