I still haven’t heard how you understand this Shach.
He’s saying why a mashuch b’orloso doesn’t make yayin nesech, not addressing why a mechalel Shabbos does. That could just as well be because of a “lo plug” (or knas) as a chashash nisuch.
What do you say about my reasoning to be matir the mB”D cholent which was placed on another fire by an aku”m (without a tzivui from the Yid)?