Spring Is it possible to change the default value of DEFAULT_CHARSET in StringHttpMessageConverter to UTF-8 in version 7.0?

I have looked at https://github.com/spring-projects/spring-framework/pull/29437, but I still insist that it's time to default to UTF-8. As far as I know, the default Charset for StringHttpMessageConverter in both Spring Boot 3 and the upcoming Spring Boot 4.0.0 is UTF-8. Since Spring Boot does not use the ISO8859-1 recommended by Servlets, why does Spring still use it?

SpringBoot4.0.0-RC1 Server

SpringBoot4.0.0-RC1 restclient