Quick answer: AMD released FSR "Redstone" SDK 2.4 with FSR Upscaling 4.1.2, which runs on RX 6000 GPUs, Ryzen AI Max chips and Ryzen Z2 handhelds, and adds Vulkan support at parity with DirectX 12. Vulkan games need to integrate the new SDK.
AMD has released its FSR "Redstone" SDK 2.4, the developer kit games use to add FSR. It includes FSR Upscaling 4.1.2, the version that takes AMD's machine-learning upscaler beyond RX 9000 and RX 7000 cards. AMD announced the wider FSR 4.1 support on October 20, and this is the SDK release developers were waiting on.
Radeon RX 6000 graphics cards and Ryzen AI Max 300 and 400 chips run the full INT8 model. A second, lightweight INT8 model, less than half the size, is made for weaker integrated graphics. That one covers Ryzen AI 9 300 and 400 laptops and the Ryzen AI Z2 Extreme, Ryzen Z2 Extreme and Ryzen Z2 A handheld chips. The model is picked automatically based on the hardware, and AMD says results vary by game, resolution, quality mode and hardware.
The other big change is Vulkan. SDK 2.4 is the first Redstone release where FSR upscaling and frame generation on Vulkan match the DirectX 12 versions. There's a catch: a Vulkan game has to integrate the new SDK to get it. Existing Vulkan games with FSR 3.1 won't be upgraded to the ML upscaler through the driver, because those driver upgrades only apply to DirectX 12 games. Vulkan games that ship FSR Upscaling 4.1.2 or newer can get future versions automatically through AMD's Adrenalin driver.
FSR Frame Generation also gets driver-assisted frame pacing on RX 9000 cards. FSR Ray Regeneration and Radiance Caching stay DirectX 12 only for now.
The Steam Deck's chip and the Ryzen Z1 Extreme are not on AMD's supported list.