From time to time my iPad suggests that it might be a good idea to enable Two Factor Authentication (2FA). After reading the help articles I gather this would make the iPad a Trusted Device, and I'd also have to have one or more phones as Trusted Phones in order to receive authorisation codes etc. However, they also say that once you've enabled 2FA on a device, you can't disable it without severely limiting some of what it can do or connect to, so it's essentially a one-way street. The help articles seem to leave a few questions unanswered, so before going ahead I was wondering if anyone here might be able to help, please.
1. If I switched my iPad off completely (I rarely do), or it restarts after an update, would I need to use 2FA to log in and get going again?
2. Every few days, separately from the 2FA reminder, the iPad wants me to "Update Apple ID Settings" because "some account services require you to sign in again". Not doing so doesn't seem to affect my everyday use of the iPad, but when I click through and enter my password, the reminder goes away for a few days. If I enabled 2FA, would that stop me getting these reminders?
3. My current iPad is a replacement for an older one which I haven't disposed of yet. If I enabled 2FA on the old one to try it out, would that have any impact on the current one?
NB - I understand this Two Factor Authentication is different from the earlier Two Step Authentication (I didn't enable that either), and the passcode that I use on the lockscreen when waking the iPad from standby. I'm assuming that if I enabled 2FA, the passcode routine would be unchanged.