Just to chuck a rock in your pool. A major disadvantage of the MCB is the ease it can be repeatedly reset by an elderly person.
A very good friend of mine (an industrial spark) fitted 60898’s in his mother’s house. The house had been re-wired to the as then current 15[SUP]th[/SUP] edition. He then went to work abroad leaving the message with mum, any problems get in touch with Tony, (I was only around the corner).
So the MCB for the immersion tripped, mother being one of those independent types reset it. It instantly tripped, she reset it again, and again, , , , , , , , , , Eventually the hot water cylinder exploded.
Had it been wire she would have had to give me a call. Plus saved me a lot of work repairing the house, Doug, her son was in China at the time so was a bit stuck as to helping out.
New isn’t always the best.
No I wouldn't go back to rewireables..... But.