Don't take the way the work rules are written to not be able to out your foot down on going over 16 hrs of duty. It's always your call whether you want to go over 16. Point 1 under that section states that "16 hrs is maximum allowable duty period." There've been a few times in the past that they asked and I said no. Usually always ended up due to some stupid rescue/repo/sitting in OKC waiting for a plane BS.
They think just because 117 allows something that they can do whatever they want. Look higher on the page and you'll see right at the top that trips will not be built to more than 8hrs flight time in a duty period. Yet because 117 allows for 9hrs now, we have 8+ hr 4 leggers. It's completely wrong. If you ever fly a 4 legger like that, fill out a work rule violation form. The day of reckoning is coming, they just don't see it yet or chose to ignore it.