I've had another look at the spreadsheet that you sent me. I'm guessing that you must have a different version of VAGCOM to me as I don't recognise that screen.
However, there is only one place that I can see a specified MAF of 850 so I assume that is the only time you went full throttle. What gear were you in? I suspect it may be a lower gear as your revs go quite high. To properly test the MAF I'd say that you need to be in 4th at least.