Hi,
I'm sorry I'm probably too late aren't I? For us that kind of waking would be OT? Equally when teething R quite often had EW or wakings around 4am. Its a painful suggestion but t worked for us... set the alarm for around 3/3.30am and do dream meds - that should (if its discomfort0 carry your LO through to a decent WU.
I know its really tough for you and it probably going to sound lame coming from me, but you know that you are doing a really great job - you're holding it all together and managing this sleep issue so well. I know it doesn;t feel like it but honestly if you go back and look at some of your earlier posts you will see how far you have come.
As for OT - with doing set naps and BT you will go through a phase of OT. Its par for the course. If you are determined to hae set tmes then i'm aftrs you are going to have to ride it out. If you think your LO is really OT then opt to do the nap 15m earlier and leave it upcapped and depending on nap lenght you could also do BT 15m earlier.
Re: the EW, I would keep your LO in his bed/cot until its a decent WU time. So decide what that is and the from WU to the 'getting up time' if you cant settle him within a reasonable time then WI/WO and tell him no its not time to get up. And then when it is, be all happy and excited and say "good morning" with as much enthusiasm as you can muster =. It will help you LO breal the association between waking up and getting up iykwim?
HTH x