My own thoughts are that the PCB solution in its various incarnations was a poorly protected and fragile stop gap measure to counter the increasing complexity and cost of external loom wiring, relays and timers. A step too far to soon perhaps before the inevitable introduction of the body control unit (BCU) used from 2014 on and allowing CANBUS interface to ECU and dash displays, dramatically reducing loom complexity and external bulky relays.
Additions like logic switching, heated screen and courtesy light timers added to existing indicator, hazard, light and heater fan control followed later by cruise, ABS and traction control all became possible within a small protected programmable box, the BCU.
