Great article, and I see the issues. Strangely enough, when watching the episode on my iPad (I know, blasphemy!) I did notice the dim light in the beach scenes, but everything was perfectly visible, so it didn't bother me. My iPad is SDR only.
HBO Max, in my book, does not deliver the best encoded signal, so it will be interesting to watch the show (in one go off course) when it arrives on Blu-ray/UHD.