It does indeed help performance on the Deck. Though not much in Act 3, which is still heavily CPU bound and isn’t efficient at all in the way it handles multithreading. In fact, Baldur’s Gate 3 still suffers with treating modern CPUs as if they were Core 2 Quads.

FSR 2.2 also does still suffer with some heavy occlusion artifacts, but in the Deck I find them much more tolerable than on a monitor.