If I have 2 phones running Graphene OS. Phone 1 will have no sim card, Phone 2 will have a sim card. I will carry them together, Phone 1 will be for public, common things, e.g., co-workers/employers giving them that number, and Phone 2 for personal/online life with no sim and only using over WiFi which is of course much safer. Would having the phone with the SIM card next to my other regular devices allow it to be linked back to me?
And would hotspotting off of Phone 2 using Phone 1 if Phone 2 is using cellular data comprise security?
If am thinking that if you are selective in the apps that you install, you only need 1 phone, especially if you have a an OpenWRT access point behind an OPNsense (or pfSense) router and a Linux computer.
Graphene should reasonably protect you from the apps that you install and from your cellular serilvice provider as well.
My guess is yes. My understanding is that hotspots use cellular data and are not routed through a VPN. I am sure someone here with more knowledge can correct or confirm that.
I tend to think there is just to much oppurtunity for these phones to be eventually linked if you are carrying them together. This is assuming the phones weren’t purchased in a way that already links them together.