Our data has columns whose value must be within a particular set of values. The ColumnsModel object's 'type' property with another property ('format' or a new property) should support this scenario, causing a combo-box control to be rendered with the valid options in the rule's value position.
I also noticed while searching the docs for this feature (https://ej2.syncfusion.com/documentation/query-builder/columns/) that your examples pretend to do this with a boolean type, creating radio buttons in the value position, but it does not accurately represent the sample data. The sample data has a 'TitleOfCourtesy' column with values of 'Dr.' and 'Ms.'. But the column data calls it a boolean type, with values 'Mr.' and 'Mrs.'. A select type would be more appropriate here.