The Founding Fathers set no such conditions. When the constitution was ratified, 3 states including the two largest and the two which were the leaders of their respective sections (New York and Virginia) explicitly reserved the right to unilateral secession. Nobody at the time claimed the states' explicit reservation of the right to secede rendered their ratification of the Constitution thereby defective. Every state understood itself to have that right.
All of such 1788 reservations were stated in terms of what's "necessary" or due to "injury or oppression".
None, not one, ever claimed a "right of secession" for any reason, or for no reason, at pleasure.
No Founder ever supported what we might call a "no-fault divorce", except by mutual consent.
Pres. James Madison, often named the "Father of the Constitution" went into this question at treat length, here.