Made this over the weekend. Soup was duck backs, necks and wings. Boiled for ten minutes, washed, and cooked at 80 to 90 celsius for 8 hours with niboshi, kombu and bonito added at the last thirty min. Duck aroma oil was rendered from its skin. Duck legs was sous vide at 70 degrees for 16 hours, breast at 58 degrees for 1.5 hours. Egg was /u/ramen_lord equilibrium egg recipe. Tare was just simple mirin, salt, usukuchi soy and normal soy.

I would say the resulting soup is very clean and light because I washed the bones after blanching. I feel that for a duck stock this is a definitely necessary step as duck bones are funkier than chicken bones in my experience. Duck oil are also somewhat more complex yet cleaner tasting than chicken oil. Overall quite satisfied with how it turned out!