How do I disable the built-in editor and automatically configure the properties of new pages?

I use a Builder plugin on the site. Members are editors and can create their own page. I want to disable Gutenberg so that they can only edit pages with Buldir. I would also disable the properties of the page for them and I would enter it automatically. When I create a new page, I disable comments, the template is Blank Page, do not access the Custom fields. You can practically just add a featured image and title to your page, then click on the Bulder link and edit it. In the page menu, I disabled Editing and Quick Editing, and I also disabled editing the page URL. However, I can't specify the properties of the new page and I have no idea how to disable it without creating a new page with the builder.

I'm trying to influence the properties of the page with this code:

function my_default_content( $post_content, $post ) {
    if( $post-post_type )
    switch( $post-post_type ) {
        case 'page':
            $post-comment_status = 'closed';
            $post_meta-_wp_page_tamplate = 'page-template-blank.php';
        break;
    }
    return $post_content;
}
add_filter( 'default_content', 'my_default_content', 10, 2 );

I could update, but it's too late after editing the page - eg Blank Page template. And even though I ban Gutenberg in vain, there is still an editing interface :(

add_filter( 'use_block_editor_for_post', '__return_false' );

Could you help me? Thanks

The WP engine changed completely in this respect around 2019. See Removing panels (meta boxes) in the Block Editor I have to approach the problem differently.

I was able to disable certain options using the code, but editors can overwrite the author of the page, which I can't disable for now. I also have problems with basic page settings - see e.g. Blank Page above.

In addition, I can't disable the Gutenberg textarea input field for editors :(