I felt like Rest in Peace was a scary enough hoser in the matchup that I wanted to run Feed the Swarm, which thankfully also has play into Urza's Saga, Blood Moon, etc. I also opted for Echoing Truth to deal with artifact based graveyard hosers. You should consider boarding these in if you see dorky artifacts/enchantments for grave hate, I mostly planned my matchups around the engine of other decks, but you could consider siding in Echoing Truth virtually all the time, in case of hosers, and you may side Feed the Swarm in against any white deck on RIP.
Esper Goryos
First you have to suss out whether you think they're going to be transforming into an Esper Blink/Control deck or if you think they're going to stay on the Atraxa plan. Both plans require a slightly different approach, the Atraxa mode is pretty good in the matchup, but so is getting you to bring in the grave hate and then blanking it.
In (vs Atraxa plan) -
4x Nihil Spellbomb
4x Consign to Memory
Out -
4x Street Wraith
2x Fatal Push
2x Overlord of the Balemurk
You want a couple of pushes for Frogs, but mostly you just want all your grave hate for the Atraxa plan. Consign has plenty of triggered abilities to hit, whether they transform or not. Overlord is a little ponderous for the matchup, so you trim a couple. If you want the Echoing Truth I'd side out 2 more Overlords.
In (vs Blink/Control mode) -
4x Consign to Memory
2x Echoing Truth
2x Spell Pierce
Out -
4x Street Wraith
2x Overlord of the Balemurk
1x Nethergoyf
1x Dark Matter Manipulator
Echoing Truth to bounce their Riddlers, Solitudes, etc in response to Ephemerate is a better plan if they transform. You leave in all the pushes if they transform to have as many answers as possible to Frog, which is mostly an enabler in Atraxa mode but is their greatest threat transformed. You trim a couple threats around the edges for Spell Pierce, which gives you some more play into countermagic and Ephemerate.
Izzet Prowess
In -
2x Echoing Truth
2x Spell Pierce
Out -
4x Street Wraith
Street Wraith is really bad in the matchup, you lose enough life to your mana base. Spell Pierce gives you answers to their removal and countermagic, and Echoing Truth is more removal that also clears up multiple Darcys or a board of Monk tokens.
Eldrazi Decks
So we're gonna go over a few here, namely I respect Trudge, Tron, and Broodscale. They all require slightly different approaches, although there are some key things that overlap in them, such as access to Consign to Memory.
Trudge
In -
4x Consign to Memory
2x Spell Pierce
2x Echoing Truth
Out -
4x Street Wraith
2x Fatal Push
2x Overlord of the Balemurk
You board in Consigns for their Yahtzee targets, Spell Pierce for Fight Rigging, and Echoing Truth as removal. Push has some targets, including Trudge, but it basically only hits enablers, not threats. Overlord is slow in the matchup, but I'm loath to cut my only enchantment when it's also an incredible enabler.
Eldrazi Tron
In -
4x Consign to Memory
2x Echoing Truth
Out -
4x Fatal Push
2x Street Wraith
Push is bad here, and Consign is good. Easy swap.
Broodscale Bloodchief
In -
4x Consign to Memory
2x Feed the Swarm
2x Echoing Truth
Out -
4x Street Wraith
4x Overlord of the Balemurk
Overlords are bad enough in the matchup that I'm willing to let the ceiling of Nethergoyf be 5/6 instead of 6/7. Street Wraith is easy to side out. Echoing Truth can pick off saga tokens and bounce Broodscale or Blade. Feed the Swarm kills Broodscale, or Urza's Saga, or even in a pinch Fleshraker. Consign answers almost literally everything outta this deck.
Boros/Jeskai Energy
In -
2x Echoing Truth
1x Disruptor Flute
Out -
3x Street Wraith
Echoing Truth answers piles of cats, whether real or token, but our engine is really good in this matchup, so I don't want to overside. Flute has uses, namely blocking Goblin Bombardment.
Blink (Jeskai, Esper, Azorius)
You side for Esper like they're Esper Goryos on the transformational plan, you side for Azorius and Jeskai like they're Jeskai Energy, because they're a Pride of Souls deck on Consign.
Affinity
In -
2x Echoing Truth
2x Feed the Swarm
Out -
4x Street Wraith
Echoing Truth can answer piles of tokens, although it is bad into Munitions. Feed the Swarm can destroy Saga or Weapons Manufacturing in addition to being extra removal for their threats. Street Wraith is bad here, and also just generally easy to side out.
Devoted Druid Combo
In -
2x Echoing Truth
1x Disruptor Flute
Out -
3x Street Wraith
Removal and threats are good here. Flute answers their tutors if timed right, and can close their outs.
Dimir (Frog/Flash)
In -
2x Spell Pierce
Out -
2x Street Wraith
The maindeck is pretty good here and there's not much in the side for the matchup. You board in a couple Spell Pierces for countermagic, board out a couple Street Wraiths because they're easy to side out and pressure your life total. If you want the Echoing Truth, board out the other 2 Street Wraiths.
Ruby Storm
In -
2x Spell Pierce
2x Echoing Truth
Out -
4x Street Wraith
Combo matchups are tough, especially spells based matchups. Street Wraith is bad here, as each one you see reduces their necessary storm count by 2, so you side in a couple Pierces and more removal for their cost reducers.
Living End
In -
4x Nihil Spellbomb
3x Consign to Memory
1x Disruptor Flute
Out -
4x Fatal Push
4x Street Wraith
Push is bad here, and Wraith is fine game 1 but easy to cut. Flute taxes Living End, and can "get them". Consigns deal with their pitch elementals, and can also counter cascade triggers. Grave hate is good here. Endurance is their grave hate, so Consign should be saved for that, often you can stack your graveyard even better than them.
Darklight Phoenix
We're still in the early days so the list isn't settled yet. However, I think Nihil Spellbomb and Echoing Truth are pretty much always coming in against Phoenix piles. Street Wraith seems bad against a deck pressuring your life total with fast birds. Fatal Push may be easy to side out if they're the all-in Phoenix pile, since removing a bird one time some of the time sounds pretty bad, but if they're like me and they're more into birds as a backup plan you may be more inclined to side down on Overlord, which is probably slow into an aggressively slanted graveyard deck.