I'm experimenting with Upscayl. It's quite good in that you can add additional models to those included. I'm yet to find one that's good for everything, it's a case of trying each. Generally there's a playoff in rendering of textures. Those that add more texture tend to look better providing they start with a cleanish image but they can behave strangely...
In general think 4xLSDIRCompactC3 does best here - one of the additional models the project has here https://github.com/upscayl/custom-models. This is also a compact model (ie. fast), it handles bigger images very well.
But there's something strange going on with the person 2nd on left merging with the texture on the rocks. Those that do better with that part of the image have mushy detail elsewhere.
