Change WordPress user roles and capabilities › Forums › Restrict or Permit access inside WordPress – how to › Visual Composer Permissions › Reply To: Visual Composer Permissions
Visual Composer (VS) button is not a true meta box. You can not block/hide it via “Meta boxes access” add-on. VC has its own “Role Manager”. Open “VC->Role Manager” menu item, select needed role and turn OFF checkbox for the ‘product’ custom post type at ‘Post types’ section just under selected role.