This server-side code will do the trick, while providing a custom message to go down to the client: return new HttpStatusCodeResult(410, "Unable to find customer.") ...

It can be client-side or server-side. As for the former, the solutions are mentioned later in this article, but for the latter, the only thing you can do is wait for engineers to do the job.

Server-side rendering as a default option for faster, SEO-friendly pages. Automatic code splitting, so only the necessary JavaScript and CSS are loaded per page.