I'm now seeing some better information on mydslwebstats and that tones in use go up to 2800. There are no obvious noise issues at certain frequencies or total loss of capacity notches.
In general the rate of drop off just seems to be very high - for example in D2 you start at 8 bits per tone and that drops to 4 at the end whereas, for example, mine starts at 10 and finishes at 9. By the time you get to D3 - there is nothing there.
Look at the Hlog graph - just treat it as one line (ignore Up & Down) and it is reasonably continuous except at the high end of U2. However, whilst it starts at just below Zero, at the very top - tone 3950 is around -80 whereas I would expect to see that at about -40. This points to the possibility of an aluminium line.
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