I did more exploration with Copilot, mainly for writing unit tests. Copilot is a pretty good at bootstraping unit tests, particularly in Java, where initializing the right types may take several lines and there is a large standard library. In doing this, the Copilot-written code was close enough that it saved me time relative to writing the tests from scratch. I learned that Copilot can show a ranked list of completion in a separate window in the IDE, which is helpful and can also be invoked with a hotkey (option+\ in IntelliJ), which is useful as well.