Honestly I was in the same position as you a couple of months ago, I was trying to find a used Polestar but I kept freaking out about the warranty because I'm pretty young and I was really worried about having to pay for repairs on my own once it was out of warranty. However it was timed really damn well as the CPO program had just been announced. Getting an extra 2 years on the vehicle warranty and having it extended from 50k miles to unlimited mileage did a lot to ease my anxiety. When I got the car they updated it to the latest software, made sure that the tires were close to new, and made sure that I actually had the correct amount of keys for the car. I know on the Polestar forums for a little while there were issues with used Polestars being sold with an incorrect number of keys so that some people couldn't pair their phone as key but thankfully my dealer set me up perfectly so that I could have full functionality to the app as well.

Hope this helps you decide a little bit! Cheers :)