Cool concept!

I think Scale of Chiss-Goria could be cut as this is an aggro deck. Upgrades could be fast mana like Lotus Petal or Mox Opal maybe even main decking Surgical Extraction.

Build both! Teshar is a great commander but it's a completely different strategy/deck. What you had with Kataki was interesting and unique. Got my creative juices flowing. Maybe I just need to design my own version.

I don't know what to think anymore. You had a very nice mono white anti-artifact/Vintage-esque control list. Now it's... This.

If this where you want to be than by a quick glance over this current build you need to add Inventors' Fair, Urza's Saga, Sun Titan and Ethersworn Canonist.

Duskshell Crawler > Nylea's Forerunner

Coiling Oracle > Urborg Elf

Growth Spiral just because it's pure value

You want a tip from me? Turn this back to Kataki, War's Wage. You had a very original concept and a solid build.

Eidolon of Countless Battles seems like a great fit.

Urza's Saga to tutor those 4 powerful artifacts.

Dust Bowl always useful with a lot of basic lands.

Coercive Portal immediately came to mind. Good value with this commander.

Rebuff the Wicked mono white staple.

Strionic Resonator double your triggers, double your fun.

Oh... Well now this is a very different deck?

Where is the Organic Extinction? And if you are feeling extra spicy perhaps Soulscour.

Ethersworn Canonist has been missing from both versions of this deck.

If you aren't using Scroll Rack than Archaeomancer's Map is better than Land Tax.

This is a really neat concept and a solid build.

Elspeth, Knight-Errant triggers Teshar and helps you win.

Eiganjo Castle protects Kataki.

Inventors' Fair seems good.

Serenity seems really good.

Land Tax is the peanut butter and Scroll Rack is the jelly.

I always suggest Orim's Chant in mono White decks.

Grave Titan? In a rat tribal deck... Major LOL.

I said my piece on cutting non rat creatures in a tribal deck. Play the deck a few more times. You will come around.

Your thoughts on adding Mutavault?

Do you think Deserted Temple would be useful alongside your big mana lands?

I saw you cut Gnat Miser. How come? Such a brutal common. If that is not strong enough have you considered Locust Miser?

This is a really solid rat tribal deck! Don't get distracted like Volrath ("If there is such a thing as too much power, I have not discovered it." - Dark Ritual)

Cut one copy of Rat Colony for the Piper. 25% is a great ratio for your Thrumming Stone engine.

You have 7 non rat creatures... I think you could afford to make 3 cuts:

Gray Merchant of Asphodel is just good stuff. Does nothing for this strategy.

Species Specialist is fantastic! while Erebos, God of the Dead seems lackluster although the static ability is neat. Necropotence does it better.

Sheoldred, Whispering One is an EDH bomb but you are already running Attrition, Dictate of Erebos, Grave Pact AND No Mercy.

Mortuary has strong synergy with the main engine Thrumming Stone

Expedition Map you are running a lot of powerful utility lands.

Great deck name. Huge fan of alliteration. It tickles the brain.

Reckless Fireweaver a value engine with that many artifacts.

Valakut, the Molten Pinnacle another value engine with that many basic mountains.

Haha! not into counterspells? Running Counterspell. That's the only reason why I suggested the artifact based Metallic Rebuke.

DreadKhan I too am a big fan of Oboro Breezecaller. Deserted Temple on a stick is extremely useful. I noticed in your detailed analysis you did not mention Floodbringer. Are you not a fan of Rishadan Port on a stick? Both offer serious utility in opposite directions.

ENVE nice budget list. Where is the Rewind and Unwind?!

Forbid seems like an auto include in a deck based off "you have no maximum hand size"

Expedition Map green like land tutor for blue. Academy Ruins would allow you to rinse and repeat.

Dust Bowl I always suggest this in mono colored decks heavy with basic lands.

Kindred Dominance and Kindred Summons quality tribal big spells.

Cover of Darkness and Steely Resolve quality tribal protection.

Species Specialist quality tribal draw.

Possessed Portal brutal stax tax that feeds Tergrid both ways.