Here's another PCB:
Then I figured that instead of fuses to protect the contacts and PCB traces, I could use Hall sensors and drop out a relay if the current exceeds 8 amps. Then I figured I may as well report the currents to users. And why not voltage too? Then it became a programmable circuit breaker module. With average and RMS voltage and current and power measurement and waveforms. And programmable ganging. And plugin fuses for bussing. Somebody stop me.