Time rule inconsistencies aside I absolutely loved this episode. I also love the implication that there are now weird monks that can see into multiple timelines and how that'll come to bite Barry in the ass. That's incredible.
Edit: Also for those of you criticizing how Barry is too slow for the new speedsters, my head canon is that it's because dude just isn't trying as hard. He's trying to pace himself cause as we saw in the scene where he goes back and forth between Iris and Joe, he does get tired. I mean over the last few months he went so fast he went back in time and killed himself, then time traveled multiple times after that, and on top of that has been fighting baddies. Maybe he's either tired or just wants to slow down a bit.