Something that might be worth mentioning regarding the proposal is around Domain terminology.
The term "Span" has been reserved by the Otel community for quite some time in reference to Open Telemetry Spans of data (see swift-otel here). I imagine introducing this terminology outside of an Otel domain within a core language feature is going to introduce quite a few unwanted namespacing collisions.
Has there been any discussions around this point and if the term "Span" is appropriate?