VernonGersch said: "And trying to wrap my head around The Shining references which I don't get."
To me, the moment that seemed the most The Shining like was when they were all covered in blood. Aside from the visual, that scene also showed their transformation into people so inside their own heads they were going crazy. That's what happens to Jack Torrance in The Shining (at least in the movie, I didn't read the book).
That same scene also crystalized why The Thanksgiving Play wasn't working for me. There's no way Scott Foley's character, given how sensitive he wants to be to Native Americans would enthusiastically hold up decapitated heads.
I found both the Scott Foley character and the Katie Finneran character totally unbelievable and overly broad caricatures. Well meaning liberals who have no context for what they're talking about is a reasonable satirical target.
However, because from the start of the play, everything they said or did seemed completely unhinged, there's no way to escalate that. It's hard to show characters have a blind spot around representation when all their behavior is strange. They can't eat cheese without it turning into a fight, they appear to have problems holding on to jobs, their sex life is apparently super weird...
Also without completely revealing the ending, at the beginning of the play, that super "woke" couple insists there's no way to do their play without collaborating with at least one Native American. Their solution at the end is completely consistent with that point. They don't really evolve as characters.