For shipping, I bought on the 18 and fot the headset on the 23, a bit longer, also I got the notification that the package was sent for delivery on the day of the delivery, was a bit weird but okay!
I didn't notice any difference between dark and bright room tracking, which is impressive.However, I did not try in a total dark environnement, qs there are always some LED, outside lamp ppst that makes a bit a light
And yes you can launch a game on the frame, use desktop mode to launch apps, then you can pin said apps in your currently running game. I did not test streaming while playing but I saw a lot of people trying it and it worked! The only issue with all that would be battery life, if you want to do that make sure you're plugged in or else you won't be playing long...