For static hold on dry days, take a look at wool dryer balls or a mild material spray made for laundry
https://charlieioqd419.solsticebrief.com/posts/down-care-how-to-clean-and-preserve-down-jackets-and-comforters
For static hang on dry days, are attempting wool dryer balls or a gentle fabrics spray made for washing. Reducing warmth and over drying additionally is helping.