That's right. You can also use `<link rel=preconnect ...>` to start a TCP handshake, which will also cause the browser to resolve the domain. But by doing these, you're making more noise on the network. The CORS request will show up in dev tools, and it is also unclear how it will behave under a strict CSP (it's worth experimenting with though).
Nevertheless, the server portion of this project doesn't care how you make your DNS queries as long as they are happening.