Except that is not true. A manifest heretic ceases to be pope ipso facto not because of a penalty incurred via canon law, but because of the penalty incurred via divine law.
We are not governed by divine law.
You remind me of the exchange between Will Roper and Thomas More:
Roper: Arrest that man! He’s bad!
More: There’s no law against that.
Roper: Yes, there is. God’s law.
More: Then let God arrest him.