The LED arrays come in individual 16x16 LED squares and I have mounted 12 such arrays on a single piece of MDF to form a 64 x 48 matrix array for my prototype (3072 LEDs).
The MDF also forms a great method of keeping the wiring neat and concealed from view and to protect the LED arrays from damage.
There are inter array gaps to allow for suitable wire bend radii for the attached wiring because I do not want to stress the flexible PCB substrate and tear tracks off.
When I create my own array PCBs these will be designed with a suitable wiring and mounting system to remove such gaps.
I grabbed a spare piece of MDF and it just so happened to be 800mm x 600mm which is absolutely perfect. I divided it into 200mm squares to evenly distribute the LED arrays.
And then drilled holes for cable ties as strain relief and to conceal the wiring on the non-display side. (Don't you think it looks much neater?)
The video is just a rough test of the wiring of six LED arrays. For this simple display the current drawn in 2.83A @ 5V.
To have twelve arrays active showing this content will require about 6A @ 5V. To power that I will have to bring out my variable 5V 40A power supply to handle the higher powered content.