FYI for all, the W3C TraceContext specification will become a Proposed Recommendation later this week. I'm one of the co-chairs of the group and am happy to answer questions about our W3C work or OpenTelemetry.
There's a discussion about "correlation context" inside of this W3C group called , which maps to what you're describing. It'd be worth reaching out to Sergey (one of the other co-chairs) if you want to find out more.
Source: Working on distributed tracing at Twilio and Stitch Fix