Yeah, that little plot development was a real doozy! And, in hindsight, entirely inevitable for a time travel story. I love how they hit me with a curveball I should have seen coming!

I'm happy to see your post here; I've been annoyed at people who quote that study and go "See? Spoilers don't matter!" I've held the same stance you describe here: there's different kinds of enjoyment, and even if watching with spoilers is a quantitative improvement, it's qualitatively different.

(And an unspoilered experience can only be had once, barring selective amnesia... though it isn't the end of the world.)