Fair point on the unbalanced braces. However,

You could assume that { and } as a structural delimiter only applies to node types that can nest. Since blobs do not nest, then a tag followed by a backtick (or multiple backticks) could be a valid delimiter in lieu of braces. In this case, tags would extend to blobs.

In my opinion, pairing minimal node types with differing delimiters helps legibility and is not overly mentally taxing to learn when node types are few.