WordPress upload_mimes not working for front-end uploads of 3D files

Thanks to this thread here, I found this code

    function fix_wp_csv_mime_bug( $data, $file, $filename, $mimes ) {
    $wp_filetype = wp_check_filetype( $filename, $mimes );
            $ext = $wp_filetype['ext'];
            $type = $wp_filetype['type'];
            $proper_filename = $data['proper_filename'];

            return compact( 'ext', 'type', 'proper_filename' );
}
add_filter( 'wp_check_filetype_and_ext', 'fix_wp_csv_mime_bug', 10, 4 );

which does allow the files to be uploaded through the form.
Not sure what I am opening myself up to, but it works for now.