YAML in Obsidian needs to always be at the top of the note. Dataview allows using other YAML like fields and the :: is their syntax. These Dataview inline fields function just like YAML but can be used anywhere in the body of the note.
I’m not too familiar with the specifics of the MetaEdit plugin. I’d suggest posting in their Github or starting a new thread, since this post is specific to Dataview and also is meant to be a showcase rather than a help post.