C.W.
Huge fan of the Weisbluth book, so I would try giving it another read. You don't indicate what your child's whole schedule is, but I'm wondering if he's not getting enough sleep (could be a cause of the night waking) and yes, there may come a time when you just have to back off. It was probably around a year or so when we TURNED OFF THE MONITOR. If he really needed us for something, we would have heard it (we have a small place, but still). I did not want to hear every little small waking and they need to learn to fall back asleep without intervention. I knew if I heard more of an "emergency cry" which would be much louder, then something was wrong. But at 14 months my son was going to bed at 6:30-7pm waking around 6 am, and around that time we started transitioning to one mid-day nap (2-3 hours). If your son is being put to bed at 9pm and not getting enough daytime sleep, he may be perpetually underrested and not able to fully "turn off" at night, hence the night wakings....