Toolbox Customizer reset theme_mod using a filter

<?php

// Toolbox Customizer > 1.6.2 needed

/**
 * these variables for LESS are define in your plugin
 * notice the filter, that's the hookname that is going to get applied
 * if more variables need the same filter you can do that like shown below
 */

'dbraflex_button_border_width'      => toolbox_customizer_css::gtm( 'dbraflex_button_border_width' , array( 'filter' => 'dbraflex_false_on_zero' ) , 'px' ),
'dbraflex_some_other_border_width'      => toolbox_customizer_css::gtm( 'dbraflex_some_other_border_width' , array( 'filter' => 'dbraflex_false_on_zero' ) , 'px' ),



/**
 * Then, somewhere at the end of the file or at least outside of the load_my_variables() function you hook this function to
 * the filter_hook
 */
add_filter( 'dbraflex_false_on_zero' , function( $value , $theme_mod , $unit ) {

    if ( get_theme_mod( $theme_mod ) == 0 ) return false;

    return $value;

} , 10, 3 );