I am aware that data migration cockpit is for initial creation and not for update. However, I have noticed that for some of the migration objects like generic long text the existing data can be updated with the use of Run ID.
Is it fair enough to call that DMC does not support update?
How can we identify how many such objects support data update or enhancement using DMC?
As it is explained in the SAP Note 2684818 - SAP S/4HANA Migration Cockpit usage for mass processing data or as interface, "The SAP S/4HANA Migration Cockpit tool and content is not built to be used as a kind of mass processing app to change or update existing data"
The tool may use API/BAPIs that can do both, creation and maintenance. It means, potentially adjusting an object using Migration Object Modeler, you may be able to also maintain. However, those scenarios are not supported (nor tested) by SAP. Therefore you should not try that option since you will not have the support of SAP.
Instead, you should explore the different SAP Fiori apps SAP has delivered for mass maitenance.
in the note it is written that the objects and structures will be adapted in the future and may not work in future releases.
But what about custom objects? If I create a custom object to change with a different BAPI, then it should not be affected by future releases, as it is also in the "Z" namespace.
Or have I misunderstood?