Gotcha. The phone number thing is a pain. Phone number is directly linked to real ID for most people. And, we know that metadata analysis is all they need to track us and who we talk to, even if they don't know what is said.

In the last few updates to Signal you can choose to be identified by a user-determined handle instead of phone number, and also choose to be only discoverable to your contacts or by no one (invite link only). Still have to sign up with your PN, though :/

I don't know if any of this matters if you are using a SIM card, though. This is where my knowledge hits a wall. Is IMEI broadcast to cell towers doxing everyone using a SIM?