Oh hugs hun, figuring out sleep is just sooooo hard isn't it? Your DD sounds just like mine in that if she is UT she wakes happy and you can't extend naps and if she is OT she wakes crying and you sometimes can extend. It sounds like she has quite a small window in which is the perfect A time for her so as not to be OT/UT. Finding it is the problem hey?!
OK, so you have tried 2h and 3h A time and still get about 1h sleep, 3h 40 gave you OT early NWings. So have you tried 3h 15mins? Maybe you could try adding 5 mins each day and see what happens? Some babies take a good while to get used to a change though so maybe only increase every few days. Do you think that would work to extend her naps and then eventually drop that CN?
Also I think taking her into your bed is also not helping. I say this from my own experiences as we have been doing this due to teething the past few nights. So last night the tooth has popped and she was medicated before bed and all seemed fine. BUT our DD kept waking all the time, I would settle her with just a hand on her and then leave and she would wake again. This went on and on so I caved and she came into our bed where she instantly snuggled up to me and DH and fell flat out asleep! There was clearly nothing wrong she just wanted us and our bed. She is staying put in her cot tonight no matter what!