I’m sure you’re already aware of this but you can mitigate this to some extent with a depth card material. Won’t work in some situations (like thru-tunnels where you can see the other opening) and it really works best for outside-looking-in scenarios. Inside-looking-out is a much more difficult problem, but I think it can probably be done.
(obviously still not as realistic as a scene with real world lighting values with properly set exposure)
His lighting is uniform mainly because he it’s planar surfaces and his interior is lit only by a skylight. Worth noting that nearly all realtime GI solutions will also produce flat lighting (except SSGI and brute force/final gather gi). They can’t indirectly shadow anything unless it is huge, and even then the quality will be poor a best because the indirect lighting approximation is too sparse to capture any detail. This is visible in your AC video you linked earlier; absolutely nothing in the scene is generating indirect shadows and the light is bleeding through base of the walls. It’s also true of RTXGI (except without light leaking)
Supposedly Lumen will generate indirect shadows, but I can’t tell from the video how this is done or what kind of quality they will be.
As of now we’re basically all just waiting on Lumen which we will hopefully get to see soon.