Thanks for reaching out! The keys here are randomly generated. The setColumnOrdering & getColumnOrdering apis default to use the column "source" names, rather than the randomly generated keys. If you have any columns that don't have a source, you could use the random key.
If you remove the "source" for a column and run a getColumnOrdering query, you'll see the same key:
You can certainly run a query to set the order - as far as I know, we aren't adding more native support for persistent user customizability in the near term (though we're tracking requests for this feature)
We will likely remove the columnOrdering property from the table since it isn't very useful and the keys aren't user friendly