I would check the Wish List here and see if this change has been requested. If so, vote for it! (Kudo or comment or both) If not, then add your request.
Given that it might be a long time before it is adopted, you might use the Recode command the Cols menu to make the changes. You could also adapt this script and run it when you get a new data table from SmartSheet.
Names Default to Here( 1 );
For Each Row(
:Country = Match( :Country,
"Great Britain", "UK",
"Korea (South)", "South Korea",
// and so on to the last change,
:Country
);
);