My current list is
I am liking this list thus far.
I cut Vryn Wingmare because it's not a Human and because 3 is way more than 2 and added a fourth Thalia because this deck really needs Thalia in play.
Spirit of the Labyrinth has been good thus far. It is also not a Human but it's such a beating if it stays in play and helps to keep from falling as irretrievably behind Gush decks if you aren't able to just Thorn them to death.
Containment Priest is the weakest creature in the deck unless it's in a matchup where it's amazing. The interaction with Displacer is fine. I experimented with Canonist in this spot (and also instead of Spirit) but I was underwhelmed. I'm sticking with Priest maindeck for now. Maybe because I feel like at least I can fallback on the Displacer Combo to get me out of a tight spot.
Revoker is amazing. As is Though-Knot. Lodestone is a dumb card that I take out vs. shops but which sometimes just wins.
I like Reality Smasher but I shaved one to find room for two Endbringers for top-end finishing, theoretical card draw, and a way to close games without attacking. This was suggested to me by @sodoyouwearacape on Twitter last night and I like the theory but I haven't actually cast one yet to test it.
Containment Priest and Displacer are the creatures that most often get sideboarded out in some number for me. I don't have a ton of confidence that that is completely right but they are the most situational.
I would be playing some number of Horizon Canopy as suggested by @wappla but I sold them last year as part of my (successful) campaign to obtain paper power. So no regrets there, I'll get some back and test those out at some point. I do like having so many basic lands, though.
I tried to make the maindeck decent against Gush (and blue in general) as well as Storm/Belcher combo. The sideboard is basically six more cards for dredge and eight or nine for shops. For assorted blue decks usually I just bring in a Swords or two, a Disenchant, or Jitte in, depending what exactly I'm playing against.
The biggest issue with the deck so far is getting white mana, especially in games two and three but it hasn't been too terrible most of the time. Maybe Horizon Canopy would lead me to be less ambitious with white cards in the board but Swords, Disenchant, Rest in Peace, and especially Kataki are so impactful that I like having access to them.
Playing the correct lands not just for the current turn but also to set up potential future draws is really tough and interesting.
In the past I've tried Shops a bit but generally I've played various blue decks. It feels weird that I never draw cards, tutor, or even shuffle (that will be even weirder when I play the deck in paper for the first time). The bottom 45 cards in my library basically don't exist unless my opponent casts Timetwister. I find that... I kind of like that.
In general I'm enjoying playing the deck and I'm looking forward to seeing where it does in the next few months. If anyone has any feedback or comments on anything I'd love to hear it.