I got the PCB's and the assembly at a discount from JLCPCB. They were kind enough to provide me a coupon code in exchange for this article and a review.
The pcbs are 4-layer boards with a total of 1154 vias between them and no shorts were made on all boards. As far as I can tell no defects are visible and the boards look near perfect.
Two of the five boards were assembled in fab like the one pictured above. There are no defects in the assembling nor shorts or missed components.
I can tell from this project that they're a good fab for PCB manufacturing and assembly for DIY projects.
Each LED is capable of outputting 16ma, for a total of >9A. I ran the matrix with 4 A and the board gets hot really quickly. I dont recommend running it at high current for long periods of time.
Since we have a total of 576 LEDs and according to the WS2812B Datasheet, each LED require 24 bits of communication to display its color and each bit takes 2.5uS+-600ns we can calculate the maximum frames per second which is between 29-38.