The ancient Chiss that remained unmarried were invalid if they chose not to marry — a case of former familial bloodline hierarchical structures that drove the Chiss to civil war.
The experimenting with outsiders means that our controlled familial bloodline environments require backcrosses to outsiders to save our species from extinction. Or…
It means those families not regulated by strict marriage bloodline families could join Ruling Families based on merit.
Thus, our current Ruling Family system begins.
But that is still a limitation on gene flow creating a bottleneck effect.