The answer to the headline question is simple: WAAAAAAAY far out.
Proof: When Debbie Pelley is quoting Phyllis Schlafly about the radical nature of your ideas, you are in Rod Serling land
They — and others far more moderate — say the idea Rapert cheerleads for a constitutional convention is nuts. There'd be no way to limit it to the Rapert-supported idea to let a majority of states control the federal budget. And that idea alone is bad enough. Next thing you know, somebody might use the convention to propose a constitutional amendment for bike lane funding.