That’s interesting. I wonder what the protocol is. Probably a simple polling of registers. There didn’t seem to be an interrupt pin exposed.
There is similarity with the riban modular revision 1 panels which have 8 knobs or buttons & 8 buttons with all 16 having individually accessible RGB LEDs. This board is a bit cheaper though.
I wonder if there is benefit in making the riban modular panels able to interface with Zynthian? Maybe a USB-CAN interface.