Layovers less than 10 hours? 10 hours is the FAR 117 minimum. Are you talking about into a DH only day? The PWA prescribes the opportunity for 8 hours uninterrupted for any duty; not just flight duty period. I can't imagine having less than 10 hours, but enough time behind the door to sleep for 8 of them.

12 G 3. A pilot who does not arrive at their layover hotel in time to be afforded at least eight hours of uninterrupted sleep opportunity at such hotel will, upon arrival at the hotel, inform Crew Tracking that the pilot will:
a. be unable to report as scheduled, and
b. require eight hours of uninterrupted sleep opportunity from the time the pilot reaches their hotel room.