For the modding community, searching for usually yields 1fichier, MegaUP, or Torrent links. Always scan NSPs with NSC_Builder before installing to verify they aren't tampered with (brick risk is low, but verification is smart).
Mastering the Art of Kung Fu: Sifu on Nintendo Switch – Updates and DLC Guide Sifu Switch NSP UPDATE DLC
Verdict: The DLC transforms Sifu from a one-weekend story into a permanent roguelike rotation. If you find an NSP pack that includes the DLC, it is the definitive edition. Sifu Switch NSP UPDATE DLC: A Game-Changing Experience