The problem is compounded by the arcane supply regs – to fit the switch you need to pull the incoming fuse to isolate the supply before fitting the isolator switch, but….only the DNO can legally pull the incoming fuse & replace it, although many DNO’s turn a bit of a blind eye to this, given the hassle of trying to get all the trades & DNO lined up.
If they do want an isolation switch for every install, then that’s me out, in my old house (grade 2 listed – so no tearing up walls/floors thanks) I have to use a convoluted cable routing that cannot be a spur from the incoming supply before the main CU (the isolation switch is to kill the power to allow the second, dedicated mini-CU to be fitted just for the EV chargepoint).
Mind you, still heard nothing back from BP, 1 week to hand-over, new car at dealers, appointment for hand-over made for next Friday.
In life, it's not who you know that's important, it's how your wife found out.