The [<googa>https://thepihut.com/collections/raspberry-pi-store/products/status-board-pro |Status Board] </googa> from The Pi Hut is just about the simplest and most affordable controller available for Box Of Stops.
While it was clearly not designed with this in mind, the combination of five input buttons (available cheaply separately), each with two related LEDs is ideal to drive a few controls in Box Of Stops.