ASUS ROG Ally Optimized Settings
The ROG Ally can run Stalker 2 at playable frame rates as long as you're standing still, especially once you enable FSR frame generation, which works great on the ROG Ally. Sadly, the game is a stutter fest even in its vanilla state, without UE5 Global Illumination, as soon as you start moving around the map since the ROG Ally simply doesn't have enough memory to run the game smoothly.
We used the 30 W (25 W when on battery power) Turbo power profile, set everything aside from textures to low, set the resolution to 900p, and allocated 6 GB of memory to the iGPU. We then enabled FSR frame generation. This settings combo gave us anywhere from about 30 to more than 70 FPS, but the heavy stuttering—just look at the frame time graphs on the ROG Ally screenshots, they look like seismometer readings during a massive earthquake—rendered the game completely unplayable. With these settings you can expect an hour or less of battery life.
Now, it looks like Stalker 2 can work without being a stutter fest on a Radeon 780M, as long as you have enough RAM.
As shown by RandomGaminginHD, you can play Stalker 2 at a relatively stable 30 FPS with Radeon 780M on a machine with 32 GB of memory. In other words, you might be able to play Stalker 2 on an ROG Ally X, if the game allows you to use the embedded controller, of course.