Where the "extra quality" search term makes more sense is in the realm of PC emulation. Many users download NSP files not for a physical Switch, but to run them on PC emulators (like Yuzu or its successors).
If you are looking for legitimate digital or physical copies of the game and its premium content: : You can find the Batman: Arkham Knight Premium Edition which includes the main game and the Season Pass. Green Man Gaming : Offers the Batman: Arkham Knight Steam Key for PC players. batman arkham knight nsp extra quality
still remains the gold standard, followed by modern console versions. included in the Switch's Arkham Trilogy or how it compares to the PlayStation Where the "extra quality" search term makes more
Third-party "extra quality" mods exist for users with modified consoles: Resolution & 4K RSS Green Man Gaming : Offers the Batman: Arkham
For those using the "Extra Quality" NSP on emulators like or Yuzu (Early Access), the results are stunning. Because the Switch code is lighter than native PC code, emulators can brute force the graphics.