Hi, tbh I'm pro DF as I liked the consistency of it. It doesn't work for all LO's though.
Do you feed at the other two NW's hun or can you resettle without feeding? Is it easy enough to get him back down or is it hard work??
If you're feeding at both, I'm wondering if that first nap might be a little too early in the day hence the wu at 5.30am? It's around now they like to extend their A times pretty rapidly as they prepare for the 3-2.
As it's been going on so long, it may just be habitual WU's and you could try w2s an hour before he usually wakes, but that'll be trial and error to find what time suits and many mummy's are awake enough times during the night that setting an alarm an hour before the usual NW then lying awake waiting to see if the NW happens tends to drive them a little cuckoo! I know it did me! Xx