It was not meant to be an exhaustive list, just meant to illustrate that the only way to get rid of it is to avoid the features that probably led them to pick Unreal in the first place.
With regard to deferred/forward, this shouldn’t matter because the lighting contribution is just summed together whether you split it up into a bunch of passes or not. In Unreal there are some shading features that don’t work in Forward and someone could pick up on that. Unreal is also very, very far from the only engine to use deferred shading, Doom the Dark Ages is deferred, as a recent example.
Unreal’s approach to lightmapping is unique (as is every engines) and I suspect that’s the biggest factor in the difference of appearance between Prey and DIshonored, because Dishonored used lightmaps.
If you gave me 3 games that just used standard fully dynamic lighting, shadowmaps, lods, MSAA/FXAA, proper color grading and no GI… I don’t think I could tell you what engine any of them was made in (except Godot, because it applies a dithered blur to its shadowmaps)
If you gave me three tonemapper comparisons between Filmic, GT7, and AgX, unless they were specifically crafted to reproduce the six color problem, I could not tell you which was Filmic.
Meanwhile, give me literally any game with Lumen and I could easily tell you it was a game with Lumen. Every game with metahumans looks like a game with metahumans. Every game with TSR looks like a game with TSR.
All the biggest, most important features are the ones that stick out like a sore thumb.
If we were talking about path traced screenshots, I might agree, but these features all have extreme artifacting, particularly under motion, that just make them very visually distinct. The technical implementation of features leaves its mark on the image, you cannot separate the “technical components” from the picture.