New Apple security feature reboots iPhones after 3 days, researchers confirm

If this is true, then it's a trivial enhancement to make that a configurable setting. 72 hours could be the default, if your security needs are higher, you could turn that down to 12 hours, or even less.

If this were configurable, I would make it 30 minutes and increase it if I noticed any inconvenience. But I doubt that I would. I already have my phone in permanent do-not-disturb (so a reboot causing delayed notifications wouldn't be an issue), and it's not like I mind entering my passcode instead of FaceID every 30 minutes.

I don't trust FaceID (technically, I don' trust the cops with FaceID), so I'm entering my (6 digit) PIN every time I take my phone out of my pocket anyway. The only thing that'd make me hesitate to set this down to single digit minutes would be the risk of missed calls/notifications while the phone reboots.

If you're outside the house that's less secure, because a security camera or a shoulder surfer can see your PIN.

Graphene has a feature exactly for this which shows a shuffled unlock screen

This sounds like an excellent way to make it even easier for people to watch you enter your PIN.

Once you’ve had the PIN scramble turned on for a while, it becomes second nature. I enter my GrapheneOS scrambled PIN about as quickly as the unscrambled PIN on my non‐GrapheneOS work phone. But it’s more of a defense against figuring out my PIN from the finger marks on my screen.

In environments where shoulder surfing is a concern, I prefer to use the multiple profiles feature: log out of my main profile (which is actually a secondary profile) to completely evict its keys from memory, and switch to a burner secondary profile containing no personal data, which unlocks with my fingerprint for convenience.