No data reported - New Relic APM agent

A repeatable development environment should start the New Relic APM agent consistently across clones and containers while keeping development telemetry separate from production. The goal is predictable agent behavior with clear visibility into whether telemetry is being sent, dropped, or intentionally suppressed.

Configuration precedence between newrelic.yml and environment variables can produce a silent no-data condition where the agent starts without errors but does not appear in the New Relic UI. License key reuse across dev clones can trigger a documented license validation failure for Infrastructure components. New Relic does not prescribe a single pattern for dev data isolation, leaving a choice between disabling the agent, routing to a separate account, or tagging and filtering by app_name.

What is the documented precedence order for APM agent configuration across language agents in current releases? What decision criteria apply for dev telemetry isolation when fidelity and production data pollution trade off? Is there a supported way to make a no-data condition observable without changing agent defaults?