Function recorder_from_env_with 

pub fn recorder_from_env_with(
    configure: impl FnOnce(&mut Builder),
) -> Result<(Recorder, Runtime), Error>

Available on crate feature dial9 only.

recorder_from_env, plus control over the Tokio runtime it builds.

configure receives the runtime builder (pre-seeded with enable_all()) to set worker counts, thread names, and flavor. What gets recorded is still driven entirely by the DIAL9_* variables.

#[dial9::main(config = || dial9::recorder_from_env_with(|t| { t.worker_threads(8); }))]
async fn main() {
    /* ... */
}