Persona 4 Arena Ultimax on Nintendo Switch has received a Version 1.0.2 update focusing on stability improvements and minor performance optimizations to reduce crashes. While bringing the game to version 2.50 of the arcade balance, this update does not introduce rollback netcode to the Switch version, unlike the PS4 and Steam versions. For more details, visit GameFAQs. Persona 4 Arena Ultimax just got a 1.0.2 update! - GameFAQs
As of this writing, the latest update for P4AU on Switch is Version 1.1.1 (released April 2023). This is the “hot” update you need.
To update a game via NSP on a modded console, you typically need the following: The Update NSP File: persona 4 arena ultimax switch nsp update hot
Safety Precautions:
Version 2.5: The Switch version is based on the updated arcade balancing. Persona 4 Arena Ultimax on Nintendo Switch has
Portability and Accessibility: With the Switch, players can now enjoy Persona 4 Arena Ultimax on the go. The game's controls are perfectly suited for the Switch's Joy-Con, offering a seamless experience whether playing at home or on the move.
The game made its way to the Nintendo Switch, and you mentioned an NSP (Nintendo Switch Package) file, which is a format used for Switch game data, often associated with digital distributions and backups. Persona 4 Arena Ultimax just got a 1
It sounds like you're looking for the NSP (Nintendo Switch game package) and update files for Persona 4 Arena Ultimax on a modded/hacked Switch (using custom firmware like Atmosphere).