I don’t think there is a way to have that with 100% sharp edges and clean connections while showing object-based “logical” orientations. With clean connections, I have in mind geometrically sound constructions.
In my teenage years, I learned to be a technical draftsman, and constructions like that are the core skills to create. One develops an eye for quality. In other words, perhaps I’m too picky. Quick ways often have downsides, hence why I used the roundish version first and ignored the square profile in your initial image. Since that is “The example of the fourth dimension”, typically the animation question comes, which gets tricky with squares.
Here is my way to produce the initial example: Scene/project file and screen capture.
From my point of view, there is nothing that a clean manual build model can beat.
Yes, I understand the idea of push-button solutions. If it is a request to avoid knowledge and skills, I’m unavailable. If we had that for everything, everyone could press those buttons. With that, most people would be out of work in no time. So, be careful what you wish … Don’t get me wrong; I’m all in for powerful and intuitive tools with lots of options. I know one thing for my work with certainty: working on things for a while focuses creativity and creates solutions that I don’t have with instant results options. But that just me.
To orient the sub-elements in those scaffolds, you need to understand the use of rails if you like to use Splines. Especially how to set them up quickly. This is perhaps simple for a cube, but it becomes fast a “puzzle” for more complex shapes, and there the artist is needed.
If you have a question, please provide scene/project files, as I’m not happy to work from images; they often tell only half the story, or here, take a lot of time, as they were more or less misleading.
Perhaps explore the Bevel tool, to create Bevels, and then delete anything else. After that Extrude with “Create Caps” on.
Example: screen capture and project file
Enjoy your modeling exploration.
(Image left, full manual; right, bevel-extrude)
Click thumbnail to see full-size image