10 and 12 read pretty much as "you give us permission to manage your devices usage ...and you must maintain our ability to do that by using the app and connecting the car. Go 30 days without it and we can boot you off". I agree it's worded a bit vaguely, but I doubt you'd have a leg to stand on if you didnt allow any IO controlled charging on a tarrif that does everything to say IO should be controlling your charging. But if you want to treat IO as GO and keep strictly within the T&Cs as written, just keep re-authorising before that 30 days expires and let them control 1 chargeAll it says is you have to leave the IO app connected to the car. It says nothing about other usage and doesn't even imply it.. I don't know where people are getting that from.
It's in the app under accounts & settings --> Intelligent OctopusAlthough I've been searching for 20 minutes now and I can't find the paragraph being quoted, so a link would have been nice.