No, you've refuted nothing I argued.
Dred-Scott had nothing to do with Fugitive Slave Laws, but rather with a slave-holder who transported his slaves to a non-slave state.
By the laws of free-states like Pennsylvania in 1787 and others in the 1800s, if slave-holders brought their slaves into free-states for extended time periods, those slaves were freed, and that's just what happened to Dred Scott.
In 1830 Scott was taken to Illinois, then Wisconsin Territory where he remained until 1838.
By laws of both Illinois and Wisconsin Scott was a freed man.
And such laws were recognized in Louisiana, where Scott could have sued in 1839.
In 1846 in St. Louis, Scott tried to purchase his freedom from his previous owner's widow, who refused and so the court case began.
So the issue in 1857 had nothing to do with the Constitution's Fugitive Slave clause, and everything to do with the rights of states, recognized in 1787, to declared their lawful slaves freed after extended stays.
That's why President George Washington cycled his slaves in and out of Philadelphia when he lived there.
It says nothing about time periods or cycling people in and out of jurisdiction. It simply says a laborer (slave) will be returned to the person to whom their labor is due. (Slave holder.)
Till that bit was amended, there was no legal way to ban slavery anywhere.
What happened was that all the states agreed to this, and then a bunch of states decided they didn't want to honor this agreement, and so they just ignored it, or asserted "States Rights", or some other such legalized excuse to break the agreement.