Interesting project, but I can't say I've ever wondered whether or not it's time to touch my Yubikey. Authenticating with a token is a very intentful process.
So you need to approve the usage of that secret by touching the yubikey.
It happens sometimes that I forget that's what it's waiting for. I'm no longer on Mac though. I have KDE. I don't always see the key flashing either because sometimes it's buried under the mess on my desk (I know...)
It's a bit annoying that yubikeys don't just trigger a hid event or something, as far as i understand the only way to tell is by looking for some obscure log entries.
You can't use a screwdriver handle as a hammer then complain it doesn't work to your expectations.
(It's true that if an attacker slipped in a request right before I was expecting to tap my YubiKey, I would tap it a second time to get my operation to succeed under the assumption that it didn't detect my touch the first time. But I would become suspicious if that kept happening.)
But yeah like someone said below, many actions like github pull would need it. I just want something that makes it easier to see it's waiting for me.