Open APIs

We need to embed the contact(medium) info's into a TMF621 ticket.

A construction via partyRole looks correct in the sense that the contactMedium information may depend on the role the party is playing:

"relatedParty": [
          {
            "@type": "RelatedPartyOrPartyRole",
            "role": "customerContact",
            "partyOrPartyRole": {
              "@type": "PartyRole",
              "name": "Customer Contact Role",
              "role": "customerContact",
              "engagedParty": {
                "@type": "PartyRef",
                "id": "474730717",
                "name": "Sam Smith"
              },
              "contactMedium": [
                {
                  "@type": "ContactMedium",
                  "contactType": "telephone",
                  "preferred": true,
                  "@schemaLocation": "https://tmforum.org/TMF632/PartyManagement/PhoneContactMedium.schema.json",
                  "phoneNumber": "0032467384756"
                },
                {
                  "@type": "ContactMedium",
                  "contactType": "email",
                  "preferred": false,
                  "@schemaLocation": "https://tmforum.org/TMF632/PartyManagement/EmailContactMedium.schema.json",
                  "emailAddress": "Sam.Smith@ispX.com"
                               }
              ]
            }
          }
        ]

The TMF621 specs only allow to use partyRoleRef:
 

relatedParty    [
The related party(ies) that are associated to the ticket.

RelatedPartyRefOrPartyRoleRef_FVO
description:    
RelatedParty reference. A related party defines party or party role or its reference, linked to a specific entity

@type*    [...]
@baseType    [...]
@schemaLocation    [...]
role*    [...]
partyOrPartyRole    PartyRefOrPartyRoleRef_FVO{...}
}]

What are the best options to solve this this - taking into account that we don't want a complex process where external party's first need to create their own contacts via TMF632 in our database? Do we 'fix' it and change or add a relatedParty via a PartyOrPartyRole_FVO (like is available on productOrder/productOrderItem/product/relatedParty?)

MEF has it own approach & solution - custom separate class, but that totally neglects the party (role) approach..:-(

See also my other question related to contact(medium) info: TMF622 - How to embed contact info - not possible on product order level via PartyRole? | Open APIs 

Thanks for your advice.