OpenTelemetry .NET 1.20: ConfigureSampler lets libraries wrap the app's sampler
OpenTelemetry .NET 1.20.0, released on October 15, 2026, adds TracerProviderBuilder.ConfigureSampler. A library can now wrap the sampler the SDK resolved from SetSampler, OTEL_TRACES_SAMPLER, or the default, instead of silently overwriting it.