Custom logo sizes for multiple logos

It’s possible to modify the size of the custom logo with:

// Modify the custom logo size
add_filter( 'image_downsize', 'wpse241257_new_custom_logo_size', 10, 3 );

// Display the custom logo
the_custom_logo();

where our filter callback is defined as (PHP 5.4+):

function wpse241257_new_custom_logo_size( $downsize, $id, $size )
{
    //-------------------
    // Edit to your needs
    $size = [80,80];          // Array of width and height
    // $size="thumbnail";   // String value of the image size name
    //-------------------

    remove_filter( current_filter(), __FUNCTION__ ); // Important to avoid recursive loop
    return image_downsize( $id, $size );
}