My understanding of all this is pretty half-baked, and the subject matter is WEIRD, but here goes:

First, I’ll bet that any experiment that attempts to peak at a quantum particle’s location will result in a collapse of the wave function no matter how cleverly the experiment is devised, like all such experiments have shown in the past. You’ll get your 7 billion year retracement.

Second, I think a many-worlds interpretation doesn’t suffer from this 7 billion year backward time travel explanation, which is a bit hard to swallow. The light from the quasar took different routes to arrive at your experimental apparatus. When you look to see which route it took, you’re simply determining which route it took in YOUR version of reality. There’s another researcher in another equivalent reality seeing a slightly different result. Actually, there is an enormous hall of mirrors number of researchers checking and getting different results from the same experiment.

Um…does that make sense to anyone?