We were advised not to use yaml but to use our own custom yaml-like frontmatter. I would like to do this, right under the yaml frontmatter, but I would like to have it folded or in Metadata box just like the current yaml frontmatter:

Perhaps we could have a box like this called “Custom Metadata” or something?
I could use a smaller header, like h5 for example, but I’m concerned about using h5 before h1 where the title goes - I don’t know if it is good form to mix up the header sequences.
Suggestions?
Note: I’m currently using h2 at the end of the file, but I’d really rather have it up top for quick editing.