OpenTracing supports adding tags to a given Span. See https://opentracing.io/docs/overview/tags-logs-baggage/#tags
Submitting a PR shortly...
PS. OpenTracing has been merged with OpenCensus into OpenTelemetry. Here's a ticket for adding support I found https://issues.apache.org/jira/browse/CAMEL-14531?jql=text%20~%20%22opentelemetry%22
However while opentracing should eventually be deprecated, there's a good amount of functionality that's not yet available in the new project (eg. the javaagent support). So there's value is continuing to support opentracing until the new project reaches parity.