Best: Repeal of Amendment 17
Worst: States power to override Federal statute by 3/5 vote.
What he’s missing:
Sunset all laws and taxes. Every one has an expiration date and must be reenacted.
Okay, your favorite is a structural amendment. His others are also structural in nature, which cannot be gotten around by activist black-robes. Taken as a whole, his changes would not only re-federalize the government, they would super federalize. Currently unaccountable leftist courts and administrative agencies wouldn't have the final word, for the states could overrule regulations and overturn Scotus decisions.
No argument from me regarding the sunset of laws and taxes.