So near-filed and far-field are basically relative to the speaker design,
For sure beside of the acoustic ratio and timing and direction of reflected versus directed waves importance, the design and the type of speakers play a great role ... Thanks for reminding us of this important fact ...
But if one listen nearfield and dont control acoustically the timing and direction of reflected versus directed waves with acoustic treatment in the room near the listening position , the result will be a no existing soundstage or one located only between the speakers ...
As you pointed to yourself:
Essentially near-field listening gives you a listening experience similar to that of headphones, but with imaging and perhaps sound-stage.
Nearfield listening with speakers is better well done than most headphone listening save perhaps with the best headphone in the world , in my experience, because of the soundstage which is out of our head, unlike almost all headphone ( save my K340 ) ...
My near listening field encompass my listening position , is holographic and way out of the speakers plane in width and depth ... My speakers cost , so good they are , is very low then it is not the result of a superlative design ( i modify the porthole and the tweeter for sure) but the result of room acoustic and vibrations resonance controls, crosstalk control to some extent also ...
Room acoustic cannot be replaced or being disposed of because we listen nearfield ...