Go agent high_security mode X-NewRelic-Id forwarding with X-Forwarded-For proxy trust

Distributed trace correlation in New Relic relies on the Go agent propagating X-NewRelic-Id across service boundaries. In high_security mode the agent applies additional header filtering, and the interaction with X-Forwarded-For from proxy chains defines a configuration boundary for correlation.

The desired behavior is consistent trace propagation when requests pass through a proxy chain while high_security remains enabled. The interaction between high_security header filtering and proxy trust flags is not clearly specified for agent versions around 8.5 to 9.2, where header filter logic was refactored to prioritize proxy trust.

What proxy trust configuration is required for X-NewRelic-Id to be forwarded when X-Forwarded-For is present? Does high_security mode suppress the header independently of the proxy trust list? Which agent versions exhibit header suppression under untrusted proxy conditions?