> The light control set up is fail-safe. If something with the RPi goes terribly wrong, we could still operate the lights in the “classic” analog way.
(I wish they'd explained how they do it, but I assume they use latching relays to switch the actual lights, so RPis and light switches can work in parallel)
Using the chrome debugging protocol for the remote screens is also quite clever.
From there all you need is two (or more) diodes to handle multiple pulse inputs. Some pulse relays even have diodes built-in (i.e. can handle multiple inputs from the get-go).
You can easily spot this sort of installation - wall-mounted light switches only go one way, and return to original position as soon as let go. And each press changes on/off state - sort of how Caps Lock works.
Note, however, that switching voltages/currents higher than rated will likely shorten the life of your relay.
Also, solution for jamming relays are SSRs. In practice there were issues only with two biggest light zones with multiple lamps switched at the same time.