Yes it will be interesting to see what difference the 1h morning nap makes. I don't think he'd be ready to actually drop a nap just yet, but the 2-1 transition can take several months and starting to cap one of the naps is just the beginning of the transition, I think I started that around 10mo for both of mine, and they only fully made the transition at 18mo! Well actually, DD isn't completely there even now
Oh and they only dropped their 3rd nap at 8/9mo - so if yours dropped it early, I wouldn't be at all surprised if he needed to start the transition process around now.
The feeding seems reasonable to me, especially if he's at a good weight for him and eating solids well. I wouldn't worry about getting too much from solids, each LO weans slightly differently and if he's feeding as much as he is and having normal stools (and wet nappies?) then I'm sure he's getting enough milk.
Please stick around here for support with your routine and night wakings rather than letting your DH persuade you to do CC
I know how horrendous sleep deprivation can be, but there's always another way that doesn't break the bond of trust that your LO has with you, and we will walk with you through this
I forgot to ask before, what are you doing when he wakes at night, for those wakings where he doesn't feed? And how does he respond? When he feeds, does he resettle straight away, or take a while to get back off after finishing his feed?