I actually gave strata SSS a shot a few days ago, and the results were…inconclusive. I only ran initial tests on simple strata materials and a few parameters, and SSS in UE5 is one of the less intuitive pieces of tech on the engine. I don’t fully understand what my parameters control (or if they’re even hooked up to actual material behavior), but it appears strata supports most expected SSS features. It’s still a diffusion-based approach, which I’m not super happy with, as RT SSS allows for much more accurate and complex light transport behaviors.
For lumen, I couldn’t say. I built UE5_1 yesterday and I’ll do more tests.