For the best experience, you need: Base NSP + Latest Update NSP.
There are two primary ways to handle the update on a modded system: sonic mania plus switch nsp update patched
The Nintendo Switch operating system tracks the latest known update for a game title. If you install an older update or only the base game after your console has already registered that a newer update exists, the system will block the game from launching until that specific update is applied. DLC and Base Game Desync: Sonic Mania Plus is treated by the system as the base Sonic Mania For the best experience, you need: Base NSP
According to reports, the initial release of Sonic Mania Plus on the Switch (version 1.00) had some issues, including: For the best experience