I'm not expert here and I have my own NW with my LO
but he's super low sleep needs and just loves to be awake LOL so I'm not expert but this advice is just from my experience.
So the EW is most likely too short an A in the AM. If he can do a 3hr A in the second 1/2 of the day and do a 1.5hr nap that's what I would shoot for. Can you APOP from 5am-6 to get him to sleep for an extra hour for a day or two while you extend the A time? I would rock my LO for a couple days to get him to a more doable wake up time of 6am and then start from there. If he fights and fights you may just have to deal with the OT and start extending his A to say 8 then 8:15 then 8:30 over a few days to get him to a 9am nap time or whatever nap time you want him to be on.
Have you noticed if your LO is high sleep or low sleep needs?
The NW may be because he's OT by the time he hits bedtime. I think by extending that first A you'll solve that EW. As for the 10:30 wake up you can always shoot for a super EBT of 5:30 so that he's not OT by bedtime if he tacks on lost day sleep to night sleep. Or you could shoot for a CN for a few days to get him to bedtime. Mine never did so EBT never worked for me. In fact I had to move his Bedtime from 6 to 7 to get a 6am wake up and he still wakes for the day at 5am sometimes. It's a work in progress for us. But honestly I have found that extending that first A time solves the NW and EW and helps organize the rest of the day.
I know how tired you are believe me we have lo's the same age and mine has NEVER slept through the night with severe reflux issues and mspi so know that you are not alone.
Let me know if this makes sense.