Switch 2 system update adds Handheld Boost Mode for Switch games
via en-americas-support.nintendo.com
Short excerpt below. Read at the original source.
Nintendo has pushed out a new system update for the Switch 2, and the star feature is one that’s been much requested: Handheld Boost Mode. This mode allows the Switch 2 to run original Switch games in handheld mode as if they were docked in TV mode, increasing resolution and performance.