At the bottom of the page there's a link to an article on hand wiring this keyboard: https://makerdiary.com/blogs/mechanical-keyboards/a-hand-wir.... That article in the list of materials lists 'Pitaya Go': https://github.com/makerdiary/pitaya-go. From that page I also found to https://makerdiary.com/collections/frontpage where you can buy one. And the code from the hand wiring post: https://github.com/makerdiary/python-keyboard.

It's a bit expensive at $30 but seems a lot better than the Pro Micros normally used with QMK, and the shop has other form factors which are cheaper. With WiFi on the chip too this could potentially push forward the frontier of cool keyboards.

I wonder how hard it would be to make a split keyboard with these. Probably you could do I2C over a TRRS cable.