Hi Karl,
Thanks so much for your kind comment! I'm so glad you enjoyed the essay.
The question of consistency among observations is a fascinating one. For me, the key insight comes from Rovelli and from the lessons of horizon complementarity: there is no view from outside the universe, no superobserver who can see across reference frames. That means that any time two observers "compare notes", the comparison is itself an ordinary quantum mechanical interaction. That is, if I compare my observations with yours, the act of comparison takes place within a single reference frame - mine or yours but never both simultaneously. There's no "view from nowhere" from which we can compare two observers' perspectives independent of a reference frame.
I just had the chance to read your essay and I thought it was fantastic. I'll post some thoughts over on your page.
Thanks again!
All best,
Amanda