John, thanks for the clarification.
For anyone following this, this idea came back from ACF support request:
If you have named your file “page-new-post.php” then all you have to do is create a new page titled “New post” with the slug “new-post” so that the template file is used for the page.
It was not apparent to me initially, (maybe I didn’t think this way when I read things), that this was a good way to go. I imagine if you had a very long title it might be cumbersome?
If you have any comments or considerations on this John, please do so 🙂
