Neomatrix is a great idea, very nice library to add Adafruit GFX support to any size neopixel matrix. I wrote a nice demo for it: https://github.com/adafruit/Adafruit_NeoMatrix/pull/9
Here’s a video:
And blog post with pictures:
http://marc.merlins.org/perso/arduino/post_2017-04-24_Adafruit-GFX-on-NeoMatrix-and-RGB-Matrix-Panel-Demo.html
It would be nice to have Neomatrix ported to FastLED to support other LED types and the option of running a matrix as 8 strips for faster refresh rate (on teensy 3.1 for instance), but for my use a single 576 LED neomatrix is more than fast enough.