Questions about Unusual Hyphenations
According to grammarbook.com
Rule 1. Generally, hyphenate two or more words when they come before a noun they modify and act as a single idea. This is called a compound adjective.
Examples: an off-campus apartment state-of-the-art design
When a compound adjective follows a noun, a hyphen is usually not necessary.
Example: The apartment is off campus.
However, some established compound adjectives are always hyphenated. Double-check with a dictionary or online.
Example: The design is state-of-the-art.
Therefore one should hyphenate it.