Hi,

while building a custom captcha authenticator, I ran across the issue that Google recommends loading their javascript with the attributes async and defer. Currently, neither the LoginFormsProvider.addScript(String) nor the more general theme.properties scripts parameters allow specifying these parameters. I think allowing those parameters, while staying backwards compatible with the old behaviour would be a helpful addition that might even affect loading times of sites when larger amounts of JavaScript are loaded in themes or templates.

I've file #11202 where a possible implementation of this idea can be discussed