I'm almost positive it will NOT fit the S&W 5.7. The S&W ScS only fits the CORE M2.0 optic ready models. The confusing part is the s&w 5.7 uses the core 2.0 iron sights cut, but not the optics cut, as that is a modified RMSc footprint.
I ordered and will be using the EPS carry for my s&w 5.7. Freedom gorilla has a ton of YouTube videos of what optics options you have with a s&w 5.7 and how they co witness w/ the stock iron sights. He even shows how much they overhang the slide, on the sides.