This is where we are at today and it's in every airline
Which is why the better groups bite the dollar bullet and put a bit more effort into training. Going back a ways now, IPEC took some management decisions to do just that and spent both time and money on initial and recurrent training in performance and weight and balance work. I don't know that I made any of the boys into performance engineers but they certainly had a better level of understanding and appreciation of the the ins and outs than did the majority of other operators' pilots.
While we may choose to be contemptuous of bureaucrats in Canberra
I don't think there is any need for contempt. The majority of the CASA folk try to do a good job and some are extremely knowledgeable and competent.
There are many who have been prosecuted over what the law actually said, versus what the law was meant to say.
But that will only be relevant if there be a delinquency in respect of the requirement. So far as I read this thread, there is no suggestion that any variation should be other than conservative. It is a lemma that the rulebook's requirements specify the minimum standard and there is no adverse concern with those who choose to aspire to a higher placing of the bar.
Therefore the answer is: "No, runway slope is not legally required to be factored in to first segment climb through the application of CAO 20.7.1B"
Definitely the case, as several posters have indicated earlier in the thread. However, there are some situations where it might represent prudent corporate and personal risk management to do so ? This latter consideration is the value represented in this thread, I suggest. The reason for the words (looking more at the originating airworthiness, rather than the operational recasting) is that the concern was with WAT requirements. Terrain avoidance comes into play elsewhere.