Yes! Egg-actly - that way I can have a step for them to hop/flap up on.Go a head and run nest boxes the whole way along. Have the lower row stick out a bit farther for a step/ledge in front of the upper, then the shelf/roost and you're good.
And do the end 1 row of taller boxes.
Oh yes that has potential... I could then run the shelf all along the long wall under the window, along the short wall (right side) and a bit down the other long wall in a 'U' shape.
AND I can alway put a 'higher up' roost that only my 'fliers' can get up to if I want - they can use the 2.5' shelf as a launch up to the high roost along that short right side wall....