How to modify the default Mega Menu thumb size ?

By adding this filter to your child theme, you can modify / adjust the default thumbnail size within the mega menu depending on the number of posts selected.

In our example, we have mega menu with 7 posts. We added a filter and modified the thumb size to 96 x 120.
If you have selected a different post count, make sure to adjust the filter function name and hook. 

function xt_child_megamenu_7_col_thumb_size($size) {
    
    return array(96, 120);
    
}
add_filter('xt_megamenu_7_col_thumb_size', 'xt_child_megamenu_7_col_thumb_size', 10, 1);