Sorry, sorry for the outrageously long post, you may slap me on the a...
To be clear, it makes a difference to me whether a DIY proposal of a hobby designer is evaluated, or whether it is a commercial product with which a manufacturer earns money and consumers have to pay money - for the latter, I apply higher standards.
He is happy because the higher resolution of the NFS accurately catches port resonances that his MLS near field gated stuff wasn't capable of. He can now definitively put to bed the issue as to why his original measurement system didn't catch the port resonances.
What I don't like about the manufacturer's post is the presentation as if it was not possible with the "old" technology to determine the serious influence of the BR port on the frequency response of the entire speaker.
You have also completely adopted this view of the facts.
But this is untrue.
For well over ten years there have been precise instructions, available to everyone, on how to create reliable high-resolution frequency responses in the low-mid range using near-field measurements and their combination.
Everyone can read about this in the
Arta manual, for example - Section 6.7 S.121ff, specific BR-LS 6.7.2 S.127ff
I have
described this here in this thread before.
Correctly measured and performed, i.e. dual channel measurement, sound pressure level equalization of the near-field BR port measurement (green), BR-port delay correction if necessary and the near-field driver measurement, baffle step correction, one obtains for example the following:

In red the resulting frequency response of the combined near-field measurements. The influence of the unwanted BR port resonances is limited in this example (the phase shift of BR port and woofer plays a major role). Nevertheless, in this case one would choose a maximum crossover frequency of 700Hz for best results.
Every amateur speaker designer (with some experience) performs these measurements.
Unfortunately, I cannot make "correct" near-field measurements of the Sierra Luna, so I can only show the result of combining the near-field measurements from Amir's sound pressure measurements and derivate minimum phase (which is not correct).
For safety reasons, Amir measures at a greater distance from the drivers (perhaps around 10cm), thus there are room resonances in the near field measurements that further distort the result.
In cyan the combined near-field measurements (as said these are not done correctly this way) of the woofer and BR port and the measurement of Sierra Luna by Seas in anechoic chamber.

In the range above 500Hz the problems are clearly visible. If the near-field measurements are performed correctly, the result could be even clearer.
This argument in the
"Luna follow up" thread shows the whole problem with the development of the speaker.
So, where am I going with this?
Here is the measurement of the same Luna taken with the NFS at the industry standard of 1 meter. Again, this is a single sweep, non-processed measurement that is not mathematically derived from nearfield measurements...
The peaks and dips are now larger because there is more room influence due to having a further mic distance.
Let's gate this measurement and remove the room:
Where is that horrible port resonance?
Let's add a bit of smoothing:
Now, if you examine the above measurement and compare to our published measurement of our reference Luna, they do track very closely.
At the moment when room resonances are suppressed by a gate, the resulting frequency response (below a certain threshold) is strongly smoothed, depending on the length of the gate.
In standard room measurements, everything below 1kHz experiences a strong smoothing when a gate is used (which is always necessary).
The manufacturer is not yet satisfied with this already heavily smoothed frequency response and smoothes it once more.
And now look everyone, the BR port resonances are no longer visible, so there is actually no problem... and our old measurements are correct.
If such an argumentation makes a beginner, no problem, but an experienced LS designer would never argue so.
With appropriate smoothing, the influence of resonance also disappears in the Luna Seas measurement:

This is exactly why LS designers who do not have an anechoic chamber or an NFS available have been evaluating near-field measurements during development for many years.
And finally, the comparison of
@amirm's NFS measurement and the manufacturer's NFS measurement with the measurements Seas made in their anechoic chamber of the Sierra Luna.
Since it has been hinted at time and again that Amir's NFS measurements are perhaps not quite correct.
Manufacturer first, then Amir (the sound pressure levels were adjusted as best as possible)
