While NSPs are the standard for digital distribution, they are intended for use on retail hardware through the official Nintendo eShop. Utilizing these files on emulators or modified hardware falls into a legal gray area regarding copyright and Terms of Service. Always ensure you are sourcing files through legitimate channels to support the developers.
If you see an being shared online, it almost always refers to a merged package containing the base game plus these v1.0.2 (or higher) fixes. Without the update, the Switch experience is noticeably rougher. curse+of+the+sea+rats+rom+nsp+update+switch