I think our nap is pretty much gone... Bit I'm still here, lol, I think this forum is my security blanket. ;-)
I have overanalysed this whole process too. DH tries to tell me it's not a science but part of me thinks if I find the 'magic formula' then we will all be better rested and happier! I'm still looking for the perfect answer, but trying really hard to let go as there is only so much control we have over this and some kids do this transition harder than others.
I've offered the nap almost every day so he has the opportunity to nap (he has fought it tooth and nail a lot of the time) but at least in not double guessing if I should have tired or not.
It's a hard process, and sometimes a long one. In the early days I was capping nap to 1hr (never dropped much less than that it tried a CN) and BT 7pm, though he often took an hour to go to sleep on nap days. In the beginning he was doing long ONS on nap days but that changed over time til the nap was robbing ONS and now i can only hope for a 10hr ONS with a nap which makes for a OT day following.
The fact that you are here looking for ways to help DD shows me you are a thoughtful loving mamma who wants to do the best for your LO so she is well rested and happy. That's the best any if us can do. ((Hugs)) This too shall pass!