Hi SimRice,
Not sure if I can totally agree with you on the point of scarification too late in the season when the grass doesn't get the opportunity to recover fully as you suggest in your last line about nursing it back and then goes into dormant mode.
That's definitely not the best way, but I will agree with the issue of the hard scalp to avoid the issues you suggest and that's why I came up with that prognosis and leave scarification to early next season giving it the full time to come back and thicken up due to the restricted sun light issues.
Don't take this the wrong way Simon and I totally understand where you're coming from as we've discussed mowers and height of grass before in depth, but your expectation of grass is radically different to what the average home owner wants.
Cheers,
BB.