Thanks for sharing your view here.
Could you please suggest which object we can enhance here to capture such details. We had two options - milestones and errorMessages. (As first line of thought)To give an example here, lets consider a scenario where we are providing a Parcel service and our company is called "Sinha Parcel services(SPS)". The SPS delivery person is finding it difficult to locate the address (or facing some other issues) while delivering the item. She tries to provide some messages (or issue details) via SPS Mobile App. In such cases, we (as SPS) would like to share this message AS IS to our client (who is supposed to get the parcel).
At the API level, we need to store such information in serviceOrder details.
Hope this gives a slight view of the situation. Happy to hear more on this. Warm Regards, Gaurav