I really like what NYS said about totally letting go of the situation and making your H handle it. He IS an equal partner in all this and if he thinks there is a better way than the way you two have discussed, then fine, let him have his day (or week or whatever) in the sun.
Heather, I'm going to jump in on this and encourage you to take the advice of NYS and GH. Think of this as an experiment. Totally drop the rope on the S5 bedtime battle for 5 consecutive weekdays and monitor what happens. While H & S5 are doing their thing, be available physically and emotionally, but just leave them be. Let H & S5 decide when its time to go to bed. I'm guessing that after 2 or 3 late nights, S5 is going to be cranky either in the morning (let H do the morning routine w/S5 too) or as the clock approaches the witching hour. See how H handles it when S5 starts nodding off in the middle of whatever is going on.
I don't remember if you or H takes the kids in the morning, but if you have to leave at X:00, the politely tell H that you are leaving at X:00 and if S5 isn't ready, then politely ask H to take him.
Are you really jealous of H's R w/S5? I can understand that you feel like H doesn't pay attention to you. I can understand that you feel like H doesn't spend "quality time" w/you. Look at H's R w/S5. Is it a healthy father & son relationship? Does H act like a father? Is H really genuinely interested in S5? Does H love S5 like a parent? Is their R more like friends? Is this the R that you want w/H?