How to disable wordpress from overload my stylesheet styles with customizer styles

I’m not familiar with the customizer specifically, but if it does it’s style inclusion properly (via wp_enqueue_style), then you can do something like the following in a plugin:

function remove_or_reorganize_styles() {
    if ( wp_style_is('target-style-handle', 'enqueued' ) ) {
        wp_dequeue_style( 'target-style-handle' );
    }
}
add_action('wp_enqueue_scripts', 'remove_or_reorganize_styles', 99);

This assumes that target-style-handle is the handle used to register and enqueue the style and that they did not set their priority to 99. Look in their code to find the handle you need. It should be somewhere with a wp_enqueue_style call.

Priority is set to 99 to (hopefully) occur after everything else has added styles.

If you still want their styles to load ( just late ), then you should be able to still just wp_enqueue_style( ‘target-style-handle’ ) after you remove it from the que … and it should now be at the end of the list.