Agree that you don't need ADF to train for or pass an IMC test but if the MAP uses an NDB then you won't be using that approach legally
Common sense aside, do you have a reference for the legal argument?
Edit: coming back to this post a day later, I think I must have misread the text I quoted because it is pretty obvious that an ADF would be needed in this case. I can't remember what I though I read!