I've got a full grid and what I think is the "earlier situation" but I just cannot parse these two clue ....
18a - Ally yielding volume’s lost trick of painful constriction (6)
My answer is a "painful constriction" and it looks like at least part of it is a word for "ally" minus "volume" but that's as far as I get.
9d - Defender against Duncan’s descendant broken by man (8)
I have a "defender" but that's it! It seems to be suggesting a Scottish word for descendant" around a word for "man" but there is definitely no 'man' in my answer!