**hugs* I understand you being in a horrible mood. I would be too.
The only thing that helped us, was just let him sleep. Even if I got an EW the next day, at least I know he had a good nap the day before.
You know that Lyle and I have been on the EW train most of his life too. We were hovering at 11.5 total hours of sleep, just like you about a month ago. I was convinced that his sleep needs dropped until one night he was just soooo grumpy that I put him to bed
an hour early. I said to myself that I didn't care if he woke at 4. He needed to go to sleep, and I went to sleep early that night as well. And he had the best night's sleep he had had in almost 6 months. An early bedtime has never really worked for Lyle before.
We are know at about 12-12.5 hours of total sleep. Which seems about right for Lyle. He wakes happy, and willing to stay in his room. When he wakes OT, he is NEVER willing to stay in his room.
I just can't help but think it's OT because Stan as always been slightly higher in sleep needs then Lyle. So, I really would put him at about 13-13.5 hours of total sleep.
He would be happy, and functioning well if he was getting his sleep needs meet.
I know that EW stink, stink stink. BUT. And OT early waking is much worse than an UT early waking, at least in my house it is. It makes the difference between a very frustrating morning and an ok, I'm tired, but I can cope morning.
To add to the weirdness of Lyle's sleep right now.
As I told you, I've decided that I'm not waking Lyle from his naps anymore (at least for now). For the most part he has been regulating this himself. Since he is sleeping more at night, his naps seem to be right around 1h30-1h40m. But, the other day he slept 2h20m. He seems to do this about once a week. Last week I put him to bed about 15 min later because I figured I was going to get an EW. Well, I put him to bed later and I still got an EW. So this week I still put him to bed at 7:30 and he woke at 6:15 the next morning.

Now, he didn't fall asleep until about 8, but the previous week he didn't fall asleep until 8:20 and was still up at 5:15.
I don't know if it's teething (we still have two molars to go, and he is showing all the signs)
Or if it's because it's winter time.
Or if it's developmental. We are still working on talking here.

But, he's sleep has totally changed (for now) Since they are similar ages and Stan is teething too, I can't help but think that he just needs more sleep.
I've seen other moms write that. And I've always said to myself. WHAT!!!! Teething always means horrible, yucky nasty sleep here. But, for the first time, with these molars, it just seems to be the case for us.
Oh, I forgot to add. (sorry this is getting long)
I'm still sticking with the 5.5 hours of A time in the morning. That was a tip we got on the other thread you had awhile back, and that really does seem to be helping.
Yesterday I had forgotten what time he woke. I always write it down, but DH was sleeping in the bedroom. He's on nights and I miscalculated by 10 min.
Lyle is still so touchy, that he took an OT nap

Just by me putting him down 10 min to late. But, since he's in this weird cycle I didn't push him to a 13 hour day, or his normal bedtime. Like I normally would. I put him to bed early last night, by 30 min. And he slept almost 12 hours last night.
I'm not saying give up what you are doing right now. Give it as long as you think he can take it, to see if you can push through it. But..... my gut is really telling me that he's not ready to drop down to 45 min naps. I feel like most LO really do follow a basic pattern. Those that went to one nap earlier, are dropping their nap earlier, and Stan was right in the middle of all that. And only Helen is at limiting Harrison's sleep to 45 min. Even Eloys is letting Jarrah sleep as much as he needs when he DOES nap. Because he needs to catch up. I think that Stan has always struggled with bad naps making him OT at Nursery and cutting all of his naps at 45 min, is just so much for a little guy.
I know when I cut Lyle's nap down - it did take awhile for it to work

So I don't know how long you should give it. How long as it been so far?