I'm considering one of your cubes, having built one that the programming code is not expandable or open source.
The main question I have is since your led's are mounted on a vertical pcb, are they mainly viewable from only one direction?
I.e. is the rear view and partial side view blocked by the pcb?
the view angle is like in Television. But you have to consider that in total front position the rear LEDs can't be seen. But because the LEDs are on stripes they can't be seen from rear. But there are a lot of videos where the camera goes around the cube so you can imagine how it looks like. The software is really open source don't know what you mean with "that the programming code is not expandable or open source"?