TinyMCE’s “Clear Formatting” button doesn’t remove lists and headings

I need to answer my own question here. I was using the attributes from TinyMCE v3, but it needed to use the v4 format. Here’s what works:

add_action( 'acf/input/admin_footer', function() {
    ?>
    <script type="text/javascript">
        ( function( $ ) {
            acf.add_filter( 'wysiwyg_tinymce_settings', function( mceInit, id, field ) {
                mceInit['formats']['removeformat'] = [{ selector: 'h1,h2,h3,h4,h5,h6,ul,li,b,strong,em,i,span,blockquote,pre,code', remove: 'all', split : true, expand : false, block_expand: true, deep : true }];
                return mceInit;
            } );
        } )( jQuery );
    </script>
    <?php
} );