I have tried both... Chloe who is 3 now went broody and hatched 11 babies last summer. I thought "this is great! She will take a break from laying and molt those sticks!" No luck. A week after hatching day she was back to laying. Still no wing molt. Maybe these ducks are just ridiculously overly...
I'm so glad I found this thread! I've been having the exact same issue with my Runner girls. I live in Hawaii, so we don't get "winter" here. I have 4 runner girls and a drake. The oldest is 3 years old now and has never molted her flight feathers- they looks like old toothpicks. My other two...