Frankly, if the state-maintained portion is ~823 feet, that's longer than the intersection in question. It links to a bridge which would be of both tourist and local interest. So it's not just the intersection. See Florida SR 470 as a similar example in TM, although that extends beyond both sides of I-75.
There's more substantial routes out there with a single sign. Maryland is loaded with these kinds of examples (not to pick off Maryland, but there's several short one-sign routes that get the nod.)
No, I don't have it clinched...just my two cents.