Is it possible to "stop in midair 500ft AGL at the inner marker" and then to "hand fly a CAT-III" approach in a helicopter? No, it's not.
But I feel that I would be wasting my time because whatever I tell you, you will always know best. I'm out.
I don't know IMC, how should I. I'm merely presenting ideas, eager to leran about the topic by ingesting the falsification of them by the people in the know.
Pls. give it a final try.