It's already possible to get AMD's framerate-enhancing FSR 4 boost on handhelds as old as the Steam Deck - but in June, AMD reserved the right to disappoint handheld gamers by not officially bringing FSR 4 to older handhelds.
Source: [The Verge](https://www.theverge.com/games/1008353/amd-will-bring-fsr-4-to-handhelds-by-the-end-of-2026)