An anonymous solver is reported in Magpie 85 as saying, “I believe that the ‘final bits’ should be the icing on
the cake, not the start of the cooking process”: a view with which I have much sympathy. With the usual admission that I couldn't do half as well myself: the grid-filling in this puzzle bordered on the puerile, and (although I have the final construction with the required highlighting - so I speak from a position of some strength) it seems to me that the final construction process is insufficiently specified.
I do feel that the fact that John Green is faced with the even more time-consuming task than usual of having to audit the final grid construction, deconstruct it and audit the deconstructed grid deserves acknowledgement and the thanks of those of us who submit.
Incidentally, and with respect, midazolam, I didn't claim that I hadn't given anything away: I said that I didn't believe that my post gave anything away to anyone who hadn't already filled the grid and identified the instructions. Perhaps any post worth the name contributes something, it's a question of balance: I apologise to anyone who considers that my post overstepped their mark.