Like both the 2 tone and the limited cubby shapes. This with a ladder would probably be our favorite if we can make it look balanced with the other cabinetry.
Bookcase with Ladder
Because this area has 9’ ceilings, we love the ladder idea. Also like the visual of all the cubbies being the same size, but it limits what can be put in them so the image marked Favorite would be our first choice.
Again, like the symmetry of all cubbies being the same size, but not as practical. This pin is a screen shot from a video showing a secret door.