Eh, yes and no. I designed some stuff along these lines 15 years ago. At that time, 12 volt stuff was not just available, it was available with great economies

Eh, yes and no. I designed some stuff along these lines 15 years ago. At that time, 12 volt stuff was not just available, it was available with great economies of scale and a huge range of options, off the shelf. You need an automotive-qualified relay? A light? A solenoid? A DC-DC converter module? A fan? You'd have 100 choices at 12v, 30 choices at 24v and 3 choices at 48v.