twentyyearstoolate, you make a good point about the commute to work and the maximum distance that would need to be dictated.
At my company I often have flights that do not start at my homebase so my company will schedule me to arrive at the hotel so that I will have my required rest time. Let's say my flight leaves at 10pm and my company schedules me to arrive at noon (10 hours before when in the hotel away from home base) or more likely at my company, the day before. I might prefer to arrive just a few hours before my flight so that I can stay longer with my family but if I have an 11 FDP ahead of me I would not be legal if I do not check into my hotel at least 10 hours before check in time for my flight.
I was pretty sure the same would apply for your homebase but as you point out it is not defined where you should live and thus nobody actually knows how long you commute and as you point out duty starts when you check in at the airport. Therefore my previous post may be incorrect.