Comment by grapheneos

The majority of our added exploit protections are based on hardware security features and that will only be increasing over time. MTE, PAC, BTI, hardware-based blocking of USB connections/data and far more are hardware features used to implement protections in software. MTE is going to be a growing part of how we build memory corruption defenses in the kernel and userspace. Once 6th/7th gen Pixels are end-of-life and we finally flip the switch on using MTE in all user installed apps by default, we can focus even more on expanding MTE-based protections.

The vast majority of users do not use a strong passphrase. The recommended high security setup is a strong passphrase and 2-factor fingerprint+PIN secondary unlock for convenience. Using a weaker PIN for secondary users for convenience is not our recommended approach.