Looks like we may be making progress, of a sort.
Heathrow has removed the references to the "Q2 2017 biggest climbers" that were based on the flawed Q1 stats and the still unpublished Q2 results (the latter are, reportedly, due to be unveiled this week).
Whether that's a precursor to a wholesale overhaul of the published Q1 scores remains to be seen, but it's an encouraging indication that Heathrow has been investing in new batteries for its calculators.