[diggan]

> if someone has a graceful/simple way to handle the non-lowercase usernames, please come forward.

Graceful? No. But simple? Yes.

Scrape every single username on HN to some local storage (even a file on disk would be enough, HN is relatively tiny), then lowercase all of them into a second column in the file. Refresh this file once per day.

Now you have a map of UserName <> username that you can use for lookups :)