That no saving thing is an issue, indeed. My experience however is that after a break (using F2) it takes some time to refind the concentration when you start driving after the break. Maybe it has to do with realism: when in real life you park your train and say: maybe I'll continue tomorrow, or another day . But in terms of realism; you can forward the time (F1 or F4) when waiting 20 minutes or so to let some ICE's pass.