Wondering about the single point vs multi-point room correction measurement situation. Are you giving up a lot by measuring only at the listening position? As usual it depends.
I used REW to measure in six positions. The center LP, one foot right of the LP, and one foot left of the LP. Then moved back one foot and repeated. So 6 measurements on a 3 x 2 foot grid. 12 feet from the speaker is the LP.
First all 6 measures with no smoothing. Which looks rather poor. Even for a given measurement.
But our ears don't really hear that. They have some smoothing capability. So I applied 1/6th octave smoothing. It looks better. This is about the kind of smoothing in the mids and above for our ears.
Then I used an ERB smoothing filter. It looks not terrible now.
That looks better still. Our ears will hear first arrival sound mostly plus do some smoothing themselves. So the last one may be close to our perception. Above 1 khz the ERB smoothed responses fit into a 2 db wide window. Below 500 hz the room modes will have an effect of course. And something of a transition in between.
I don't know what Dirac and other softwares do, but they probably do some sort of averaging or smoothing among other things. It strikes me that any of the ERB smoothed response measurements used to EQ the result isn't going to sound radically different (maybe barely noticeable) to any of the others or even an average of them all. So single point measurements probably work okay for this.