If you're using TLDs that aren't reserved for local use, there's nothing "perfectly good" about your network. The official guidance has always been to use a sub

If you're using TLDs that aren't reserved for local use, there's nothing "perfectly good" about your network. The official guidance has always been to use a subdomains of real domain, probably in split-horizon networking if you don't want to leak internal addresses. There are a few internal TLDs you can use. You always had home.arpa available, and .example, .test, and .invalid were also reserved. Anything else is and always has been fair game. .local has had Apple-specific incompatibilities since at least 1999. Apple should've standardised .local before they released software that relies on special handling of it, but it's been almost 25 years since this problem was introduced and 11 years since this was standardised, it's time to move on.