Alpha stagger version of Cain's Vault35 keyboard.
Check out the original product and other awesome projects of Cain at https://mechvault.net/.
There are four options to fill in the space in the middle column: 1) two normal switches, 2) two encoders (or a combination of encoders and normal switches), 3) an OLED, and 4) a trackpoint module.
For TP option, refer to my phoenix45 alpha stagger repo: https://github.com/galvy0/phoenix45_alpha
https://github.com/galvy0/qmk_firmware/tree/galvy/keyboards/galvy/vault35_alpha