So, for e.g., can a gridswitch be at the back of a kitchen cupboard?
Anyone know what the regs say about this?

Yes they can. The main issue is that a person servicing the appliances can
be said to be in control of the switches. Otherwise, the switches have to
have the facility to be padlocked off. You could possibly get round this by
suggesting that the unswitched socket provides DP isolation instead of the
grid switch, but it isn't best practice and can't be used if spurs are used
instead of sockets, or the socket isn't easily accessible.

Believe it or not, there are many cretins^H^H^H^H^H^H^Hpeople, who seeing a
tripped circuit breaker or isolator will simply reset it without determining
that there isn't someone working on the circuit first.

Christian.