This article and similar threads keeps popping up in my feed, so I'm going to keep spreading this tip around. (I'm using Android.)
I use tasker to automatically lockdown my phone based on accelerometer and Bluetooth. A sharp tap to my phone or being disconnected from Bluetooth is enough to lockdown my phone and disable all biometric access. I dialed in the sensitivity so that it doesn't take much, just a tap on my pocket, being set down a little too aggressively, pulled from my car and thrown to the ground is all it takes. I set it to notify me with a quick vibrate when it does this for a little added confidence that it is behaving as expected.
For a little added effort I can have tasker snap a photo that gets backed up to the cloud any time there is a failed unlock attempt, just be prepared for some unflattering photos of yourself looking like an aging male boomer posting selfies to the facebook.