Updates April 6, 2019:
Definitely getting the workflow down, from footprint creation to the overall board layout. Also 3D viewer is quite nice.
I wanted to try out creating PCB plates as a means to avoid laser-cutting metal plates at lasergist. So here it is.
Uses a 19 mm unit size, and has pads at the bottom to support underglow LEDs in the form of an addressable LED strip (WS2811, WS2812, SK6812).
Turns out JLCPCB allows me to make inside cuts in the PCB, as long as I don't mind the rounded corners. Not much of an issue with the big 14mm x 14mm cutouts, but may be an issue when I start doing Neopixel backlighting footprints.
Any hints on how big I should make my 5050 LED cutout be?