1. As far as I can see whatever you described about Triple A isn't happening. It's simply magically buying more fuel through your tablet, seemingly instant.
2. If everything can be roleplayed why buy the game, I'll just picture it all in my head. I think there's not alot of management going on if all you need to do is bring up your tablet and buy fuel at a higher cost. Trust me my imagination is good, but that's a bit too much. I've played plenty of simulators and I can distinguish what I need to roleplay and what would actually break immersion. I think the penalty for forgetting to fuel up should be a little more than that. If I was a real farmer and I forgot to tank up what would I do? Go to the gasstation with some jerry cans and fill them up, cursing myself on the way over and back for the lost time. I think saying "just roleplay it" is too easy. Add a little depth to the whole mechanic if you're gonna put it in. Make it feel like fueling on time matters and is a bigger part in the routine than "Oops I forgot to fuel up, better alert the magical Triple A to instantly fill my tank up".