Here's the thing. W1S1 is about keeping stuff moving. But some stories just need more time. And one thing I learned last year was that some things I'd put aside because I thought they weren't salvageable actually are.
Yes, that's why I couldn't submit my first intended W1S1 story this year. I know there's something not working, and only time will give me a sense of what that is. After this weekend, I think I know, and the rewrite won't be easy. But it could do what the story needs.
I guess it depends what stage of writing you are at, but I've learned a lot in the last year, and I think I know how to attack a couple of stories that need rescuing now, as a result.
Some stories just need time to sit and stew in your subconscious for a while, too.
But the good thing about W1S1, is that you can do all that, and keep writing new stuff in the meantime. I guess the trick is not to let the stories that are waiting in the background wait there forever.