Sounds great!
For the CN I would work backwards from BT, keep their nights regular yk? So work out BT then WU will be 1.5hr before BT. If this means 45min CN then that's what I'd do, if it means 1hr then that's what I'd do. I'd continue that way until/unless over time a problem arises or a pattern they prefer becomes apparent - like for instance if waking at 45 mins means they are in melt down by BT then I'd keep CN to 1hr, possibly reduce the last A to 1hr 15 to maintain BT but also be open to a 15 min later BT (if they can't sleep after 1hr 15 A time). Hope this makes sense. Aiming for regularity of routine but also open to their preferences too.
BTW sounds great to have fed them when you woke at 3am, I always feel feeds that come close to 5am are harder to get babies back to sleep - at least mine thought it was the beginning of the day!