Storage and connected drive questions

Hi, I am new here and considering the purchase of an i3 Rex in the UK. This is a great source of information, thank you all very much. I have a couple of questions, I have searched but with no luck. I work away from home for many months each year and the car will be left in my garage for very lengthy periods, up to six months. I understand that I should charge it to around 80% before storage but should I then use a battery conditioner on the 12v battery? One such as an optimate? I can also have a friend drive the car once a month if that is a good idea? My wife will also drive the car so I wondered if you can connect two phones and apps to the one car?

Thank you very much.

Yes, just make an account, add and verify vehicle, and use the same credentials to sign into the app on as many phones as you'd like.

As far as charging, storage , usage, if its going to be operated at least a few times per month, 12v and high voltage system will be fine, a battery tender isn't a bad idea, but if garaged, shouldn't even be nec.
[for ref I test drove an i3 that was on the dealer lot, on the open roof for 6 weeks, (i3's weren't particularly popular at this particular dealer) , had to move 8 cars to get to it, sales associate brought those portable jumper units, assuming it would be dead, to our surprise it "started" up with no fuss. It was a weird moment since we didn't know if it was really "on" , since nothing fires up. ]

Don't use a 12vdc charger on the utility battery unless you disconnect the high voltage system (there's a switch for that). In reality, if you have an EVSE, you could just leave it plugged in. Once charged and just sitting there, it probably wouldn't turn back on for a week or two. The car decides when to have the EVSE apply power, it is not constantly trying to charge like your typical cellphone.

Thank you for the replies. It seems both options should be fine but I think, if I understand correctly, I can leave it on high voltage battery charge without any issues and the car will only take charge when it is required? Every few weeks or so? Does the charger also look after the 12v battery?

Thank you