This and other writings can be so frustrating. Yet again, Article V is NOT a “constitutional convention”; it is utilizing a Constitutionally-provided second mechanism to create Constitutional amendments. Ratification takes the same path as the first mechanism (Congressional-proposed amendments).
Once the Convention is called, there are no limits on how much change can be done. That being said I am all for a Convention of States because no matter how many amendments they propose, the amendments still have to be ratified by the states.