Open-source boards designed in KiCad by HWXLR8 on GitHub, from 3 repositories. A board’s address here is its repository’s there.
HWXLR8/beef-board
USB HID PCB for Bemani rhythm games
HWXLR8/yinyoudeng
音游灯 RGB LED PCB for rhythm game buttons
HWXLR8/pcbeef
A collection of simple PCB designs