There is a very strong requirement here for dead testing before the circuit is energized, both for a full installation and for simply adding a new circuit to an existing system. That applies for domestic, commercial and industrial stuff.
Not just IR testing to see if the cable is OK, but also testing R1+R2 (live and earth resistances) both to verify socket & SP switch polarity, and also from the boards Ze (earth loop impedance) to check the circuit's Zs value is going to allow fast enough disconnection by the choice of fuse or MCB, etc.