Tried out yourl evel. I had some flickering on materials and shadows but except from that ran on around 30 FPS:
Also ran the Blueprint level with my custom character and materials. Moved everything around to make sure that what I see are dynamic shadows and not basked ones, confirmed it is AHR. Runs around 20 FPS. That is around 4 FPS lower than CryEngine on my same machine for reference.
ALso I gotto tell. These shots I get with AHR… just sweet. 
Got even a hand metal reflection
And
So as a final say: I don’t know what is the deal with material/shadow flickering in Example Level but from my experence in real time GI I can summarise .
If optimsed well further, supported by Epic and combined together with DFGI for terrain system would be ready for “commercial purposes” (meaning production of games, films etc)
Cheers mate. Bloody good work