Re Amex:

Since the pandemic, in the main section there's no longer seating at the counter, which is a shame (although probably not for the OP who has children with them). If you enjoy cocktails, the bar has a far better selection of ingredients than any other lounge I've encountered in HKG including Pier F. As I mentioned earlier, I have seen it filling up, although the last time I was there in the evening a couple of months ago it was fine. I guess I have an additional reason to go as there's caviar in the Centurion section, albeit a tiny portion.

Re PP:

Certainly my limited experience of one PP lounge, and seeing the queues evident outside others, I'd plan elsewhere, although the new Chase lounge might be worth a try.