Why not us-east-2 if you need east coast? Even so, I’m almost as far as I can be (in America) from us-west-1 and us-west-2. The difference in speed is barely perceptible when running services out west. In fact, I think my Lightsail PiHole is out there.
As I said, I’m not aware of any historical issues at the other DCs. 🤷🏻♂️
East 1 is the default, so you have something there. Not sure why a fault in any given region would affect others? My PiHole didn’t go down and I would surely notice a lack of DNS. :)