I wired up a big range cooker today in a new house. 14kW ish. A 32 Amp 6.0mm2 circuit. Final meter of T&E in 4.0mm2. The big worry is that we could not find a cooker switch on the wall anywhere, just the cooker connection plate. Perhaps not needed by the Regs. nowadays, but nice to turn off when cleaning the cooker, servicing it or in case of emergency, or last thing at night to stop children fiddling.
I warned the owner that it is not a good idea to turn on all ovens and hobs at once.
Z.