The Ghoul by u/tzarc is a Planck-like ortho but also a development board for QMK.
KBD.news Published June 29, 2022
So tzarc, designer of the Djinn, made another dedicated development board to aid the work of developing QMK support for various hardware. Thus e.g. the hotswap MCU you don't see too often on keyboards.
RGB 128x128 OLED
SparkFun MicroMod for hotswap MCU support — current QMK compatible with STM32F405 but "known-working with the in-flight RP2040 PR"
hardware support for MicroSD, SPI EEPROM, SPI NOR Flash.
uses 74HC589 SPI Shift Registers for key matrix.
The miscellaneous hardware are testbed features, in the author's words: "for me to develop support for QMK on, like external flash, SD card, custom diode-less matrix, etc."
Kinda hard to get some of the components right now, but hey, if you can get them, go for it! – tzarc.