Unable to exclude metabox field with Meta Box Include Exclude

I am using Frontend Submission and trying to exclude a metabox field from frontend. I have tried the following:

$meta_boxes[] = array(
    'id'         => 'projects',
    'title'      => 'Setari proiecte',
    'post_types' => 'proiect',
    'context'    => 'normal',
    'priority'   => 'high',
    'fields'     => array(
        array(
            'name' => 'Continut',
            'id'   => 'bgt_content',
            'type' => 'textarea',
            'rows' => 20,
            'exclude' => array(
                'ID' => array( 48 ),
            ),
        ),
);

and

$meta_boxes[] = array(
    'id'         => 'projects',
    'title'      => 'Setari proiecte',
    'post_types' => 'proiect',
    'context'    => 'normal',
    'priority'   => 'high',
    'exclude' => array(
        'ID' => array( 48 ),
    ),
    'fields'     => array(
        array(
            'name' => 'Continut',
            'id'   => 'bgt_content',
            'type' => 'textarea',
            'rows' => 20,
        ),
);

But none of them are working.