Fundamentally Watchface implementations are quite different from Android Views/Compose UI. They draw to a canvas, while Compose UI does support Canvas elements and it's basically drawing to Canvas underneath (not reusing legacy native views), you would need to implement your own non UI Compose runtime. It's possible, but a lot of work for you to get started, unsupported and unlikely to be as efficient as the code you write to draw each frame in a Watchface.