For what it's worth, I think you can save yourself the effort. Since we all would end up with different max hours recorded to get to zero you would only be another datapoint. At least, in my case it appears I could record somewhere near 260-270 hours of my mix of programs preGenie. Now around 240. If you finish your experiment you will only know what zero works like not what being at "below" zero works like. I've already experienced what you're heading for and it's no different than before Genie.
Yeah, I got the idea last night and started before reading your first post.
I may let it go to 50%, just to get some idea, as early in this thread, 180 hours was looking like what the limit was.
"We know" we won't have as many hours as before, but it does look like DirecTV could still be fair saying "up to 200 hours", and most would get the 200 hours.
For those living on the edge and exceeding the 200 hours before, this may not be much help.