Problem is that it has no inverter. It also fails...a lot. It does more than control the indicators, it works alongside the ECU and if it fails, you are unlikely to turn the engine off, even if you take the key out. Over running is ok as you can stall the car,starting it again is another matter. The part is cheaply made £50 or so which means production is likely to be £5-10 max.
The opposite of over engineering is required so that it does fewer tasks in a more reliable fashion.
