There are good reasons to agree with both sides but it is definitely possible to achieve excellent results with proper prompting. I am sure many of us have seen this promiment example from NASA:
What I see being discussed in this thread is to find a way to enable developers of custom GPTs to protect their work, which is still IP, to a higher degree.
And the way how I understand the comment from @N2U is to pretty much forward the user request to another server, process the request and run some checks on the output.
It would probably be a good match to create a custom GPT that can walk a developer through the process of setting this up properly.