If you set the Access-Control-Max-Age header [1] it will at least cache the preflight response for up to 2 hours in chrome.
[1] https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Ac...
[1] https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Ac...
That said, it would be cool if static hosting services like S3 offered CORS proxies for uses like this. I wonder if that's a thing.