I'd be careful - search specifically for a fully refundable (no penalty) fare without regard to class, as they could have Y fares that are unrestricted (for changes) but not refundable.

Also, I'm not familiar with the terminal where AC operates at EWR - if there is another airline from the same gates (not just the same terminal) like UA, DL, etc., buy the ticket from them so you don't need to drag your passport to the airport to check-in.

Obviously don't tell anyone at the airport what you're doing - but the process is easy enough and is undetectable (unless you keep doing it every week). I've done it plenty of times without an issue.