The inability to secede is in the logic and definition of a constitution.
Conditional ratification was never an option for the state ratification conventions. The question was to be answered with a “yes” or a “no” not a “yes, if...” It was explicitly voted down at the NY convention after receipt of the Madison letter.
The states were never truly sovereign most did not even have constitutions as states until the Union was formed. Americans fought for NATIONAL independence and the generation of the Founders thought of themselves as one People.
It was that PEOPLE gathered in conventions in the states (for administrative convenience) which ratified the constitution.
In reality, Congress EXPLICITLY forbid ratification by state legislatures PRECISELY because, if considered as just another state legislative act, it could be revoked by another legislative act.
St. George Tucker quotes don’t change these facts. Nor do they refute what I said. In fact, he specifies how the Union could be CONSTITUTIONALLY changed. A procedure the Slavers never tried.
Would the Constitution have been ratified if the states thought they couldn't exit at will? I think not. It is ridiculous for any student of history to think otherwise. The perpetual union thing is BS.
Since you are playing fantasy history here, if I had any say in the matter, each state legislature would have to vote every 4 years to STAY in the USA, the default would be to leave the UNION and become independent.