@jonathanmatthews If you go to GitHub Copilot itself (https://github.com/copilot) there's a (...) menu in the top-right with a feedback option. Annoyingly I can't link directly to it.
@sethmlarson I think that might only be present somewhere beyond the "free signup" page ... which I've thankfully never completed :-)
@jonathanmatthews Ah lucky you, they "gift" Copilot access to some open source folks (and keep emailing me to remind me of this gift I can't refuse). Maybe there is another place you can send feedback.