Ok typing this from Sputnik running on efika with Mos 2.1

I too had an issue with usb dropping keyboard on the open firmware but i put this down to usb to ps2 converter i was using,
I dragged out a usb keyboard and mouse and the install worked flawlessly

@zyphoid
Are you using normal usb keyboard and mouse or any type of converter?
BTW My USB to ps2 adapter works perfectly once 2.1 is installed

Gaz