I think for me personally, a second GOS pixel would make the most sense. Not sure if this is useful or overkill in your case.
One phone with mostly open source apps, without your name tied to it. Some countries still sell SIM cards without ID. Or no SIM. Would make a private phone I guess. Maybe giving this number either to nobody or only family etc. Phone constantly in airplane mode. Only off airplane mode when you are a few km away from home, if you have a SIM. Would be very annoying to do constantly though.
The other as your secure but less private phone but still better than stock android. With apps that need user accounts with your name etc. Even with a SIM card tied to your name. Can still be strict with permissions and airplane mode exists.
I feel like this is required, if you want to use loyalty programs of shops, or mobile payments, or not feel bad about using some social media apps.
Like an onion, outer layer pixel for stupid stuff and less important people to contact you. The core pixel for private/business stuff and as emergency contact possibility.
It is difficult to plan this out in your head correctly, how you want to separate.
Atm I only have 1 phone. I don't leave it at home like the other user, but it stays in airplane mode often. I think in an emergency I don't want to be without phone. And you can play offline chess or something if you need to kill time at least.
One thing I thought about, putting a address in the emergency contact information with a "reward $" info for bringing it back - so if I do lose it somehow, it will be locked anyway and its impossible to locate it right (airplane mode)... So if a good soul finds it, at least he knows where to give it back. Obviously not everyone wants this.