Hey!
At 2y, My DD was doing 2h in the day and 11.5/12h at night. She i think it average bordering on HSN.
I think that the change at nursery may be having an effective and may be affecting your naps. Also there is a developmental thing (language for us) at 2y which played havoc with our routine.
I think that you should go with your gut. If you think that 12.30 (capped at 2h) and 7pm BT are right then that os what you should do. I now that all Los have different sleep needs, but to me based on what my LO is like, what you are suggesting is appropriate.
If you suspect that you may be going through a wonky period because of nursery or developmental stuff, I wouldn't tweak - I would do what I can to stay consistent and manage the sleep to avoid OT.
What do you think? What's your gut feeling?
Hena