source for masonry image size

i know that filter : avf_modify_thumb_size – and i can change the masonry size to f.e.:

function enfold_customization_modify_thumb_size( $size ) {
$size['masonry'] = array('width'=>1210, 'height'=>1210, 'crop' => false);
return $size;
}
add_filter( 'avf_modify_thumb_size', 'enfold_customization_modify_thumb_size', 10, 1 );

but that will need a recalcultion of that size to take effect on my existing masonries.

isn’t there a way to have by that a new-size :

add_image_size( 'new-size', 1210, 1210, false );

function my_custom_sizes( $sizes ) {
    return array_merge( $sizes, array(
        'new-size' => __( 'New Size' ),
    ) );
}
add_filter( 'image_size_names_choose', 'my_custom_sizes' );

and to set this new-size as source for masonry thumbnails?

______
For Example
On av-helper-masonry.php i can see that function: prepare_loop_from_entries
there we have : $img_size = 'masonry';
is it possible to use the filter avf_masonry_loop_entry_content to change here the source ?
Thanks