Depending on the site it might be practical to detect JS on first request and set a cookie to indicate that the new format (and polyfill) can be sent on subsequ

Depending on the site it might be practical to detect JS on first request and set a cookie to indicate that the new format (and polyfill) can be sent on subsequent requests instead of the more common format. Or for a compiled-to-static site just use <NOSCRIPT> to let those with no JS enabled to go off to the version compiled without support/need for such things.