I have updated my LED signs with an ESP32 processor and LED Dividers. The hope is to eventually support some sort of graphics. Maybe even design it on your phone and upload it to the sign.
Here is a project by someone else that supports 16x16 graphics on your phone:
I also made an instructable for this project:
The biggest change was to add dividers between the LED's. This picture is of the dividers being installed on the left. As you can see it makes a big difference.
This time I used zig zag wiring where each line goes inthe opposite direction. At one end they get looped back by some 30 gauge wire. At the other end they get power as shown in the second picture below.
You will have to print out six of the design missing two sides and six of the design missing one side. Then they are glued together ontop of the LED strips. I added weights to hold the arrays to the sign while the glue was drying.
I used a ESP32 processor wired as shown below. The code is on the instructable.