Fractional distillation relies on different liquids in the alcohol having different boiling points. The people who apply the denaturants selected them very carefully to keep the boiling points as close as possible. It is much more difficult than you imply.
“It is much more difficult than you imply.”
You’re wrong, but I guess you’re accustomed to that. By your comment, I see you are more interested in contradicting than learning. Good luck with that.