I've been using OctoWS2811 for my xmas display for years. Last year I ran 8000 LEDs from two OctoWS2811 adapters, which has worked great. (https://fredrik.hubbe.net/chaosdisplay/ for more information)
This year, I'm planning to go for 10000 lights, and I noticed that the OctoWS2811 library now supports Teensy4.1, potentially driving all the digital outputs in one go, which seems nicer than having a whole bunch of OctoWS2811 adapters running in parallel. Also, the USB speed is starting to become a problem with the OctoWS2811 adapters. So I went ahead and designed a quad-octows2811 adapter which I call DuotrigintiWS. It's fully capable of running 32000 LEDs at 30 fps. (Or 16000 LEDs at 60 fps)

Here is a first test video showing it in action.



I will be sharing full details of how to build these on my website, including kicad sources and BOM, but that will take a little while.
For anybody who is really impatient, here is an oshpark link for the PCB: https://oshpark.com/shared_projects/HavteW8o