How to output choices from a custom sortable checkboxes control via Customizer settings

I’m trying to dynamically output some settings from theme Customizer. I use this custom controls, Example 3.

How can I display the settings so that the selected options appear as well as in the order in which they were placed in Customizer?

So far I’ve tried without success:

    $  box = get_theme_mod( 'sample_pill_checkbox3' ) ;       switch ( $  box ) {                  case 'author':                 echo 'Author';                 break;                  case 'date':                 echo 'Date' ;                 break; } 

Basically, if Author and Date is selected and Date is placed first, so I would need to appear in the frontend, Date first then Author.

Thank you!