I find it interesting that Lockdown Mode doesn't (yet) enable multiple lock screen authentication methods. Requiring Face ID AND a pass code could be useful. (There are rumors that Apple will add Touch ID back to their phones in the future. I'm not sure they'd keep Face ID on a phone with Touch ID but combining those two methods AND requiring a pass code would seem to be the most secure.)

I'd also like to see some method for quickly wiping the phone or severely disabling it. A friend mentioned that a new scheme for thieves is to ask you for your unlocked phone at gunpoint and then use a cash app to transfer money to one of their accounts. Some way to very quickly (and covertly) wipe your phone would help defend against that attack. (Related: https://www.startribune.com/warrant-grifters-targeting-cash-...)