AT,CZ,DE,ES,GB,IE,IT,PL,SE,SG

So it does include Poland. Also Google officially released this year's Pixel 8 in Poland, so there must be support centers here, maybe after all there is a chance that the Pixel 6 Pro can be repaired under Google's warranty.

How can you tell it didn't install on your phone? Phone restarts and what happens next? You get notifications on new update availability?

My phone was stuck in lock screen, I was lucky enough to unlock it by accessing settings menu from upper status bar, turned out that most of my system apps were 0 Bytes in size, tried wipe from settings menu and only then it worked!

It's my first Pixel phone and it's hard to imagine Google struggling to deliver flawless iteration of their system for their own hardware...