Well, as I understand the OP, "a belt so that one never actually needs the braces" (or vice versa) approach.It is for a belt and braces approach.
However, there's no point in adding the belt (if one already has braces) or added the braces (if one already has a belt) if the thing one adds will never do anything - and, as I just wrote, the 100A MCB would never trip unless there was a sustained load averaging more than 145A for at least an hour.
Kind Regards, John