That's not correct, Dirac Live takes nine measurements in order to be able to understand what should be corrected and what not, it does not average them in order to make a correction filter.
The above applies to both impulse response (often overlooked, I did'nt see it in your graphs) and magnitude.
More details about Dirac Live here:
http://diracdocs.com/on_room_correction.pdf
Response predicted by Dirac Live is quite accurate, the subject is discussed for example here:
https://audiophilestyle.com/forums/topic/22467-dirac-lives-graphs-how-accurate/
As you mention one can use REW but conditions have to be the same, also measuring in one single point in space is useful and possible for double checking the accuracy of Dirac predictions but is not valid for an appraisal of the listening results.. both IR and FR will change considerably even at the distance of one ear vs. the other.
We usually use both and don't put our head in a vice
These are two measurements taken at 30 cm. distance, which one should one choose for correction and evaluation of the results?
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Ciao, Flavio