$core_v2_dynamicForm.RenderForm takes a parameter ConfigurationXml

The expected way to interact with this API is to insert the XML string.  It provides a more upgrade safe approach by not requiring new versioned objects and can be updated with little to no impact on upgrades if needed. You will find similar patterns in the URL definition APIs.   The method by which you obtain this string is up to you, either hardcoded, xml file embedded resource or reference, or even a serializeable object of your own design.  In your use case, a VM or JSM template could also do this as the resulting XML is ultimately being fed to a scripted API

The expected way to interact with this API is to insert the XML string.  It provides a more upgrade safe approach by not requiring new versioned objects and can be updated with little to no impact on upgrades if needed. You will find similar patterns in the URL definition APIs.   The method by which you obtain this string is up to you, either hardcoded, xml file embedded resource or reference, or even a serializeable object of your own design.  In your use case, a VM or JSM template could also do this as the resulting XML is ultimately being fed to a scripted API