In Chrome Devtools, in the bottom panel, you can select WebAuthn, click Enable virtual authenticator environment, and create all the test passkeys you desire.
Joystick movement personally never made me feel sick but it would sometimes nearly make me fall over. Turns out having your environment suddenly shift without moving can make your body react appropriately by trying to catch its balance.
> I have one (1) Windows PC and one (1) iDevice. Can I get these to sync? Or do I need an Android phone for that?
Yes. In Chromium-based browsers, at least. Your browser will display a QR code which you scan with your phone. Your phone will display a list of accounts you can sign in with, you select one, authenticate, and you're logged in. Firefox support isn't here yet.
It can be used on both Android and iOS. Desktop machines can display a QR code which you scan with your device. Passkeys are backed up to the cloud using E2E encryption. If you get locked out of that device, you can do the same thing as when you lose your password.
Passkeys are unique per Relying Party, in this case, google.com can only access passkeys for google.com. They can't even enumerate them, all they can do is pop up a dialog and wait for the user to select one.