In Gen 15:16, what does it mean that "the iniquity of the Amorites is not complete"...is this related to "fill up the measure of their sins" 1 Th 2:16

If God is sovereign and our destiny is determined before the foundation of the earth, has God allotted a measure of sins for each of the doomed? Prov 16:4 says God made the wicked for the day of doom. Rom 9 talks about the potter making a vessel for dishonor. Did God cast out the Amorites only after they each individually filled up their measure of sin.