Google Smart Lock 4+

Well, for me it's broken with the iOS 15.2 upgrade - and it brings back the issues I've always had with it:
No support. As in, no one in Google's support organization has any clue about what this app does. No support group discussions as far as I can tell ("Smart Lock" is too generic to really find anything).
That's not surprising, because while I've figured out how it works/what it does in my use case, there's really no clear documentation on it - like what it even does, really.
I'd be more likely just to reinstall it, but the steps aren't really clear and fiddling with my access tokens isn't good when I have work to do. Getting a new phone last month I had to turn off 2SV for my account to kill ALL my keys and re-enroll them to get the new device. Glad I'm an admin!
When it works, it's helpful and works reasonably well. But, stupidly frustrating to understand and set up.

Pros: can use iPhone’s security chip as authentication hardware key
Cons: I have to open my gmail app, tap the yes button and then type in my iPhone lock key.
Why can’t they simply tap into iPhone’s Face ID to skip all these steps? I might as well type in my google password to login. Yes, it’s more secure. But it does not save me the trouble of having to type in password (in this case my iPhone lock key).

I added my iPhone as a security key and was able to use this app as my 2FA to approve logins. I’d get a notification, say yes, and move on with my day.

Stupidly, I purchased and added a titan security key from google thinking I should have one in case I lose my phone. This has completely destroyed the use of my iPhone as a security key - now push notifications to approve logins on my phone also make me use the titan security key. Every. Single. Time. Remind me what the point of adding my phone as a security key was if I need to use another security key?