Ruling: Thumbprint scan is like a "blood draw or fingerprint taken at booking."
The legal situation is more complex and nuanced than the headline implies, so the article is worth reading. This adds another ruling to the confusing case history regarding forced biometric unlocking.
Reminder that on an iPhone, if you hold the Volume Up and Power buttons simultaneously for several seconds, the phone will vibrate and will require the PIN or password next time you unlock it, not Face/TouchID. This happens whether the screen is on or off, so you can discretely do it in your pocket.
Correct. Not sure about iOS either, but many custom roms can, e.g. divestos, probably resurrection remix used to have it back when it was a thing (not sure here, but I distinctly remember having this feature somewhere before graphene)
In order to turn off the Find My iPhone functionality, you need the Apple ID password, so this isn’t even a real concern. You can even remotely lock the phone with a new password. Apple has made stealing an iPhone and making it work afterwards very hard.
Absent an idiotic carrier/mfg skin that disables the feature, you just long-press power then click "lockdown".
Or reboot the device. Rebooting the device will also leave it encrypted if your device has encryption (the PIN/password is needed to decrypt, essentially).
My Samsung A11 (android 12) has a "lockdown" option when you held the power button. It would turn off all biometrics and hide notifications. You may have to dig in the settings to enable it, though