One of the guys working on this at our company interprets the reg like the OP. He feels that while not specifically prohibiting same day commuting, if the commute takes longer than 2hrs, then you aren't in compliance based on the 8 hrs of uninterrupted sleep opportunity. It's really open to how you see it, but being that the company and the pilot now share responsibility for rest it wouldn't surprise me to see something like "must be in domicile 10-12 hrs prior to FDP start" being written into company manuals. And if you commute via air, then CASS becomes the tattle tale. Hopefully this doesn't happen.