Hi,
how it was described to me some years ago is that 'A good CNC machine and controller does not replace a skilled machinist but means that a the same skilled machinist
can do so many more jobs quickly and profitably using the advantages that CNC confers'.
The upshot is the controller itself, if it has good conversational programming features, or if the CNC control inhibits manual use. I don't know enough about Heidenhain controls
of that vintage to comment but I would be surprised if it DID NOT have all the features necessary for conversational programming and/or manual operation.
Craig