I must say that I was brought up to believe that 'an isolator' did not have to be capable of breaking a full load and, for that reason, a functional switch' (which obvioulsy would be able to break a full load) should always be operated before one operated an 'isolator' on the circuit. On that basis, 'isolators' could obviously not be used as emergency (or functional) switches.Are isolators designed to break the current while a cooker is at full load?
That terminolgy seems to have changed (or, at least, is commonly being used differently). In the present context, maybe the simplest thing to do is to forget about the word 'isolator', and merely talk about a 'switch' (which, once operated, also achieves the required features of 'isolation'!).
Kind Regards, John