@daw-kc, I completely agree with this suggestion! I've also had the Take a Break reminder turned on, but, just like you, I’ve never actually noticed the notification. In fact, I even thought the feature wasn’t working at all!
A subtle chime or a more noticeable color change (like turning red) would make a huge difference. It would help ensure that users actually see and benefit from the reminder instead of missing it entirely.
Also, totally with you on Opera Air—I've been testing it as well, and I’ve completely switched to it. It finally won me over! Excited to see how it evolves.