There aren't different rules for achieved and predicted grades in that way. If an A* in an EPQ lowers the other requirements then it lowers the other requirements.
Like someone else said, the grades in your offer almost never depend on your grades for those subjects - grades are used as a yes/no for whether you get an offer at all. (Obviously if you have achieved grades because you already sat your exams, then it's just a yes/no decision, there is no offer based on grades.)