Hi Darryl,
For enhancement requests like this, IBM typically recommends submitting a Request for Enhancement (RFE) rather than opening a standard support case.
You can submit and track RFEs through the IBM Ideas/RFE portal:
https://ibm-z-software-portal.ideas.ibm.com/
If the z/OS Connect plugin is part of a BMC Workbench integration, it may also be worth checking whether the functionality is owned by IBM or BMC. If it's a BMC-developed plugin, BMC's enhancement request process would be the appropriate route.
Including your use case (for example, copying data to/from COBOL copybooks, Swagger/OpenAPI definitions, and request/response payloads) along with the productivity benefits will help strengthen the request.
I'd be interested to see this capability added as well.