Available here https://github.com/yuzuMods/yuzuMods/tree/master/mods/paper-mario-the-origami-king
Framerate mods are an increasingly common mod type for Switch games, even more so than they were for Wii U games. I imagine partly because they're usable on actual (modded) hardware when used in conjunction with overclocking. Here's a compiled list of them https://github.com/masagrator/NXGraphicsPatches
Funny enough you have situations like the Switch version of Crash Team Racing being the only place where you can find it running at 60fps.