Here's maybe a solution: don't trigger the app if the phone is unlocked via a hardware shortcut.
At least in my last 2 phones, I got them configured such that a double press on the power button wakes the camera app immediately (great for quick photos), while the rest of the system is still locked (need the unlock pin when trying to navigate away from the camera app)
So in that situation the app could choose not to interrupt.
+1 I rely on this hardware shortcut heavily when trying to catch photos of the kids in fleeting moments.
Edit: just tested this and the nudge does not appear to interrupt the camera quick access