When using JSL, update the Make Validation Column function to accept column names for Stratified Random, Grouped Random, and Cutpoint options. I know you can use formula random and add a by(:Group) but there should be a direct way to do this.
Example:
current data table() << Make Validation Column(
Training Set( 0.50 ),
Validation Set( 0.25 ),
Test Set( 0.25 ),
Stratified Random ("My_Column_Name")
);