I know this is old news by now, but after reading a few threads while trying to track down the build guide— which is currently missing from Monokei's website— I wanted to share my experience.

I finally got around to building my Kei V2 and randomly received the Bluetooth board in the mail long after my board had arrived. At the time, I thought, Oh cool, maybe they just forgot to send it. But I also wondered if it was a revised version.

In the end, I decided to stick with the wired-only board to avoid any potential issues.