Meaning, apply consequences for the dishonesty, and then MAKE HIM DO THE WORK OVER, or do another assignment of comparable difficulty, (supervised to ensure he gets no outside help) to see how HIS work is.
I do see #4 as a tool to drill down and determine the students actual level of understanding of the topic but there is no follow up on the “other consequences”. This works for little kids but at what point to you start preparing them for the grown-up world?
Cheating should reduce the grades not just make them do it over.