So this is somewhat different from what the OP posted, so do take it with a grain of salt. My building point was Shaheen Soorani's list posted earlier this year. Mostly because I really think Elspeth and Gideon are underplayed. However, when Cruise and DTT unleashed their power on the format, Elspeth and Gideon were not good enough for the Delver/Burn and Twin meta at my LGS. I think it's very reactionary to put Kitchen Finks main deck or either because the OP thinks that U/W will be soft to Burn which I've never really found to be the case.
Lets start with the core of the deck.
3 Snapcaster Mage
Really the core of the deck. Allows us to recycle/flashback so many of our spells. It's akin to having 3 extra spells in the deck and pretty much goes without saying.
2 Restoration Angel
3 Wall of Omens
2 Vendilion Clique
2 Elspeth, Knight Errant
This will be our main game plan against other control decks. I have tried Elspeth, Sun's Champion as well as a split with Elspeth, Knight Errant. It just depends which one you're comfortable with. If you're casting planeswalkers to slow your opponent down you probably kept a suboptimal hand.
(I haven't found anything I want to cut to add Spell Pierce/Pact of Negation. I think Spell Pierce and Pact could have a home in this deck. If you have suggestions, I would love to hear them. Removal is at a premium in this deck and evaluating board states can be difficult. When to counter a threat or let it linger to Path it later is not trivial. I have lost many games countering a threat instead of just using mana better and using a Path.
Another Note: I think Shackles is too slow for modern and if B/Gx is going to be a thing then Abrupt Decay is basically the worst feelbads.)
My sideboard has never been the same from week to week. If Splinter Twin will rise in popularity now that Delver is a lower tier then Last Breath numbers need to go up. The spell does an insane amount of work. You can nuke your own guys to gain life against Mono-Red. It's an extra out against Bob, Goyf (sometimes), Goblin Guide, Monastery Swiftspear, Young Pyromancer, Wild Nacatl (sometimes). Zoo is a tough matchup. They can bring in Choke and Ajani Vengeant which are hard to deal with. But with some careful play you can out attrition the opponent using the right counters. You basically never want to let a Knight or Thrun live for too long. Thrun is the reason I was running split of 1 Wrath of God and 1 Supreme Verdict. But that is your call.
Stony Silence has never been reduced from the 3 copies. Your Tron matchup is the worst. Literal worst. I've played optimally so many times, only to be on the otherside of having a hardcasted Emrakul attacking you eventually. I am a proponent of adding Surgical Extraction and strategically using Tectonic Edges to keep your Tron opponent off Tron. Once the land is in their graveyard, Surgical Extraction the land and you should have the game.
I like bringing in fracturing gust against affinity and using your early spells to deny them Cranial Platings and Arcbound Ravagers. Eventually, you cast a Fracturing Gust which either gains you so much life and it still hits their Etched Champion! So...my rough sideboard would be something like: